COSMIC EXPANSION AND H\boldmath{$_0$}: \\ A RETRO- AND PRO-SPECTIVE NOTE
G.A. TAMMANN \& B. REINDL
Attempts to measure extragalactic distances over the last 90 years are briefly described. It follows a short history of the discovery of the expansion of space. Reasons are discussed for the decrease of the Hubble constant from $H_{0}\approx500$ originally to $H_{0}\la60$ at present. Remaining problems with Cepheids as local distance calibrators are outlined.
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%               XXXVIIth Moriond Astrophysics Meeting 

%                      The Cosmological Model
%                Les Arcs, France (March 16-23, 2002) 
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%   TITLE:  Cosmic Expansion and Ho: A Retro- and Pro-Spective Note
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%   AUTHOR: G. A. Tammann & B. Reindl, Astr. Institut Basel
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%   DATE:   30.07.2002 (final)
%           02.09.2002 (final2)
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\begin{document}
\vspace*{4cm}
\title{COSMIC EXPANSION AND H\boldmath{$_0$}: \\ 
       A RETRO- AND PRO-SPECTIVE NOTE}

\author{ G.A. TAMMANN \& B. REINDL }

\address{Astronomisches Institut der Universit\"at Basel \\
Venusstrasse 7, CH-4102 Binningen, Switzerland}

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% \leftline{XXXVIIth Moriond Astrophysics Meeting}
% \leftline{The Cosmological Model}
% \leftline{Les Arcs, March 16-23, 2002}
% \leftline{astro-ph/0208176}
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\maketitle
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%  Abstract
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\abstracts{
   Attempts to measure extragalactic distances over the last 90 years
   are briefly described. It follows a short history of the discovery
   of the expansion of space. Reasons are discussed for the decrease
   of the Hubble constant from $H_{0}\approx500$ originally to
   $H_{0}\la60$ at present. Remaining problems with Cepheids as local
   distance calibrators are outlined.
}
% **************************************************************

% **************************************************************
% 1. Introduction
% **************************************************************
\section{Introduction}
%
The conquest of the third dimension beyond the Galaxy was one of the
great challenges of the 20th century. It is not possible to do justice
to its fascinating and complex history in a few pages. Much of the
progress during the first half of the century was made at Mount
Wilson. Insight into this part of the history is provided by
\citet{Sandage:95}, and his forthcoming monograph ``An informal
history of the Mount Wilson Observatory (1904$-$1950)'' will be the
prime reference for the subject with all its ramifications into most
fields of astronomy.

% **************************************************************
% 2. Early Galaxy Distances
% **************************************************************
\section{Early Galaxy Distances}
%
The battle about the nature of the ``nebulae'' was still raging
\citep[cf.][]{Fernie:70} when the first attempts were made to measure
the distances of individual galaxies. Five steps should particularly
be remembered: 
\begin{itemize}
\item Hertzsprung's (\citeyear{Hertzsprung:14}) tragedy. He had
  determined the distance modulus of SMC from Cepheids to be
  $(m-M)_{\rm SMC}=20.3$ (115\,kpc), roughly a factor 1.8 too
  large. According to the custom of the time he transformed the
  distance into a trigonometric parallax of $0\arcsec0001$, losing a
  factor of 10 during the process. While transforming the 
  parallax into light years he lost another factor of ten. Thus his
  published distance of 3000 light years buried his sensational
  result.
\item Shapley's (\citeyear{Shapley:15,Shapley:18}) mistake. In the
  following year Shapley repeated Hertzsprung's measurement. For
  various reasons he now obtained a Cepheid distance of only
  $(m-M)_{\rm SMC}=16.1$ (17\,kpc), which he slightly increased in
  1918 and which he could take as a confirmation of his conviction
  that all ``nebulae'' were part of his very large Galactic system.
\item Lundmark's (\citeyear{Lundmark:20}) insight: He was the first
  to recognize supernovae as a class distinct from novae. This
  explained the brightness of the ``nova'' 1885 in M\,31 and led him
  to a modulus of $(m-M)_{\rm M31}=21.3$ (180\,kpc). Still much too
  low the value could not be accommodated within even the wildest size
  estimates of the Galaxy. But the result had no influence on the
  ``Great Debate''.
\item {\"O}pik's (\citeyear{Oepik:21,Oepik:22}) ingenuity. He used
  the rotation velocity of M\,31 to determine the mass-to-light ratio
  of the galaxy and he broke the distance degeneracy of this value by
  adopting a very reasonable mass-to-light ratio of the Solar
  neighborhood. He obtained a stunningly good value of $(m-M)_{\rm
    M31}=24.5$ (750\,kpc), which he decreased in the following year
  by a factor of 1.7. {\"O}pik's papers remained unnoticed.
\item Hubble's breakthrough in 1924. The discovery of several novae in
  ``nebulae'', first by \citet{Ritchey:17}, stimulated the search for
  variability and led Hubble to the discovery of a Cepheid in M\,31 in
  1923, --- the first Cepheid beyond the Magellanic Clouds. At the
  meeting of the Association for the Advancement of Science in
  December 1924 he announced the discovery of several very faint
  Cepheids in M\,31. They proved that many of the nebulae are actually
  ``island universes'', but the proof was not generally accepted for a
  while, because van Maanen's (\citeyear{vanMaanen:23}) unexplained
  measurement from proper motions of a detectable rotation of the
  spirals \citep[for a possible exlanation cf.][]{Baade:63} stood
  still in the way. Hubble published his Cepheid distance of M\,31
  only in \citeyear{Hubble:29a}, after he had published the Cepheids
  in NGC\,6822 (\citeyear{Hubble:25}) and M\,33
  (\citeyear{Hubble:26}).    
\end{itemize}

% **************************************************************
% 3. The Emergence of Cosmic Expansion
% **************************************************************
\section{The Emergence of Cosmic Expansion}
%
The great paradigms are often introduced on humble paths. Did
\citet{Slipher:14} realize that his first -- and subsequent -- radial
velocities of ``nebulae'' would be the stepping stone of modern
cosmology? The first interpretations of the surprisingly large radial
velocities were made under the impression of the
``\citet{deSitter:16,deSitter:17} effect'', which was a correct, yet
unphysical solution of Einstein's field equation, predicting a change
of the clock rate with the square of the distance $r$ in a {\em
  static\/} Universe
\citep{Wirtz:18,Wirtz:25,Stromberg:25,Lundmark:25}. Lundmark wrote ``the
smaller and presumably more distant spirals have a higher space
motion'', yet his ansatz $v=ar+br^2+c$ betrays his preoccupation with
the de Sitter effect.

   \citet{Lemaitre:27} was the first to combine observations with the
theory of expanding space. Extrapolating Hubble's Cepheid distances,
he derived a value of what was to become known as the ``Hubble
constant'' of $H_{0}=627\;$[km\,s$^{-1}$\,Mpc$^{-1}$]. A similar
analysis of the observations led \citet{Robertson:28} to imply a value
of $H_0=461$. 

   Hubble had used his Cepheid distances to calibrate the brightest
stars ($M_{\rm pg}=-6.3$) and the mean luminosity of bright galaxies
($M_{\rm pg}=-15.8$; --- either value $4^{\rm m}-5^{\rm m}$ too
faint). In this way he extended his distance scale out to the Virgo
cluster. \citet{Hubble:29b} plotted his distances against Slipher's
radial velocities and derived a value of $H_{0}=500$. This is
generally considered as the discovery of the expanding Universe. But
he was not sure what to make of his discovery and he commented:
``\dots the relation may represent the de Sitter [clock]
effect''. Considerable weight of Hubble's solution hinges on four
Virgo cluster members, which would nowadays be excluded because of
their virial motions. Hubble was lucky that Slipher had not
accidentally picked the bright Virgo spiral NGC\,4569 with its
negative radial velocity; this galaxy would have considerably confused
his first Hubble diagram. But he knew already of M. Humason's very
large velocity of NGC\,7619 (3800\kms), and in the following years he
extended the Hubble diagram in collaboration with Humason beyond
40\,000\kms \citep{Humason:36}. It is curious that Hubble, while
convincing the world of the expanding Universe with his brilliant book
``{\em The Realm of the Nebulae}'' (\citeyear{Hubble:36a}), died
with doubts on his mind about the expansion. They were based on his
unsatisfactory counts of galaxies (\citealt{Hubble:36b};
cf.\ \citealt{Sandage:95}), and his last Hubble diagram
(\citeyear{Hubble:53}) is commented ``no recession factor applied'',
i.e.\ he did not apply the full K-correction required in an expanding
Universe (cf.\ \citealt{Sandage:95}).

   \citet{deSitter:30} extended the Hubble diagram to $7800\kms$
including new redshifts by F.G Pease and M. Humason. Hubble was 
outraged and took it as an undue competition. de Sitter used distances
by Shapley, Lundmark, and Hubble as calibrators and galaxy diameters
as distance indicators. His data imply a Hubble constant just short of
500. Having discarded his clock rate effect he proved deep insight into
his result, still exceptional at the time, by writing: ``The only
acceptable explanation \dots is by the inherent expanding tendency of
space which follows from the solution \dots of Einstein's differential
equations for the inertia field''. 

   Any possibly remaining doubt about the expansion of space was
dispelled (it took a Fritz Zwicky to remain reluctant) by the fundamental
paper by \citet*[][known as HMS]{Humason:etal:56}. The authors
presented redshifts for 920 galaxies, objectively measured
magnitudes, the first correct K-corrections, and a Hubble diagram of
field galaxies as well as a tight Hubble diagram of clusters.

   In the following years Sandage (e.g.\ \citeyear{Sandage:72};
\citealt{Sandage:Hardy:73}; \citealt*{Sandage:etal:76}) started a vast
program to extend and to tighten the Hubble diagram of brightest
cluster members with the final goal to determine the deceleration
parameter $q_0$. The program came to a halt when it become clear that
(cluster) galaxies undergo luminosity evolution. But the results were
decisive subsequent to the discovery of the large quasar redshifts
which stimulated a mysticism, even among astronomers, which is now hard
to understand.

   We will return to the ultimate Hubble diagram of supernovae of type
Ia in Section~\ref{sec:08}, which does not only lead to the
large-scale value of $H_0$, but with considerable likelihood even to a
combined value of $\Omega_{\rm M}$ and $\Omega_{\Lambda}$. 


% **************************************************************
% 4. The Stretching of the Distance Scale
% **************************************************************
\section{The Stretching of the Distance Scale}
\label{sec:04}
%
\citet{Hubble:36b} has decreased his 1926 distances, and it became
increasingly clear that they had further to be decreased to account
for Galactic absorption (cf.\ Table~\ref{tab:01}). But Hubble gave
his 1936 distances to E.~Holmberg as his preferred values still in
1950. 

   Yet Hubble's distance scale was challenged by \citet{Behr:51}. He
noticed the large luminosity scatter of Local Group galaxies and he
argued via the Malmquist effect that Hubble's {\em mean\/} luminosity
was too faint by $\sim\!1\fm5$ if applied to more distant,
magnitude-selected galaxies. (This is to our knowledge the first
mentioning of Malmquist statistics in extragalactic work; cf.\
Section~\ref{sec:07}). Citing \citet{Baade:44} he also corrected
Hubble's magnitudes by $0\fm35$ (at $18\fm3$). These were Behr's two
main reasons for deriving a value of $H_{0}=260$. He would have found
an even smaller value had he known of Stebbins, Whitford, \&
Johnson's (\citeyear{Stebbins:etal:50}) pioneering photoelectric
photometry which  proved Hubble's photometric scale error to be even
larger. 

   The revision received much more weight when \citet{Baade:52}
announced that work in M\,31 had shown, that either the
zero point of the Cepheids or of the RR\,Lyr stars must be in
error. Since Sandage's (published \citeyear{Sandage:53})
color-magnitude diagram of M\,3 had shown that the RR\,Lyr stars are
correct, the Cepheid luminosities had to be increased, as
\citet{Mineur:45} had already suggested. Baade concluded that
``previous estimates of extragalactic distances \dots were too small
by as much as a factor of 2'', which led him to $H_{0}\sim 250$.

   Accounting for the first four years of research with the $200''$
telescope, \citet{Sandage:54} summarized the evidence for $H_0$ and
concluded $125<H_{0}<276$.

   \citet{Humason:etal:56} estimated $H_{0}=180$ on two grounds: 
(1) They showed that what Hubble had considered as brightest stars of
NGC\,4321, a member of the Virgo cluster, were actually HII
regions. The brightest stars set in only $\sim\!2^{\rm m}$
fainter. 
(2) The absolute magnitude of M\,31, resulting from its apparent
Cepheid modulus of $(m-M)=24.25$ \citep{Baade:Swope:54}, could be used
by the authors to calibrate the upper-envelope line of their Hubble
diagram of field galaxies on the assumption that the luminosity of
M\,31 must be matched by at least some galaxies.

   The confusion between brightest stars and HII regions was
elaborated by \citet{Sandage:58}. The corresponding correction
together with the correction of Hubble's photometric scale led him to
conclude that the 1936 distance scale was too short by $4\fm6$ and
consequently that $H_{0}=75$. He noted that if the brightest stars had
$M_{\rm pg}=-9.5$ (which is now well demonstrated) $H_0$ would become
$55$. He also concluded from novae that Hubble's Local Group distances
were more nearly correct, i.e.\ too small by ``only'' $2\fm3$ on
average (cf.\ Table~\ref{tab:01}). Sandage's paper has become a
classic for not only having  given the first modern values of $H_0$,
but also because it contains the first physical explanation of the
instability strip of Cepheids.

   The situation in mid-1961 was summarized by \citet{Sandage:62} at
the influential 15th IAU Symposium (cf.\ Table~\ref{tab:01}). While he
cited values of $H_{0}\sim110$ by \citet{Sersic:60},
\citet{vandenBergh:60}, and \citet{Holmberg:58}, his own values ---
based, in addition to Cepheids and brightest stars, on the {\em
  size\/} of HII regions --- were 75$-$82. F.~Zwicky pleaded in the
discussion for $H_{0}=175$ from supernovae.  

% ******************************************************************
%  Table 1: Distances of nearby galaxies from 1936-2002
% ******************************************************************
\begin{table}[t]
\caption{Distances of nearby galaxies from 1936$-$2002.}
\label{tab:01}
\begin{center}
\begin{minipage}{\textwidth}
%\footnotesize

\bigskip
\begin{tabular}{lclccclclcl}
%
\hline
\noalign{\smallskip}
 & \multicolumn{3}{c}{Hubble} & & \multicolumn{2}{c}{Sandage}& & \\
 & 1936$^{*}$ & 1950 & $(m-M)^0$$^{**}$ & \hspace*{0.5cm} 
 & 1958$^{***}$ & 1962 & \hspace*{0.5cm} & 2002$^{\dagger}$ & \hspace*{0.5cm} 
 & Factor  \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
% ******************************************************************
LMC       & 17.1 & 17.1 & 16.7 && 19.2 & 18.4  && 18.56 && 1.08 \\
SMC       & 17.3 & 17.3 & 17.0 && 19.2 & 18.78 && 19.00 && 1.11 \\
M\,31     & 21.6 & 22.4 & 21.8 && 24.6 & 24.16 && 24.47 && 1.14 \\
\noalign{\bigskip}
NGC\,2403 &      & 24.0 & 23.6 &&      & 27.6  && 27.65 && 1.02 \\
M\,101    &(25.5)& 24.0 & 23.6 &&      & 27.7  && 29.36 && 2.1  \\
Virgo     & 26.7 & 26.8 & 26.8 &&      & 30.8  && 31.6  && 1.4  \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
$H_0$     & 526  &      &      && 75 & 77$\pm$20 && 58$\pm$6 && \\ 
% ******************************************************************
\noalign{\smallskip}
\hline
\noalign{\smallskip}
\end{tabular}

\medskip
$^{*}$ Hubble's 1926 distances are $0\fm5$ {\em larger} \hfill
$^{\dagger}$ as compiled by \citet{Tammann:etal:01b} \\
$^{**}$ corrected for galactic absorption \\
$^{***}$ from Novae
\end{minipage}
\end{center}
\end{table}
% ******************************************************************

% **************************************************************
% 5. A New Start on the Distance Scale 1960-1990
% **************************************************************
\section{A New Start on the Distance Scale 1960--1990}
\label{sec:05}
%
The still unchallenged (within the errors) Cepheid distance of M\,31
of $(m-M)^{0}=24.20\pm0.14$ \citep{Baade:Swope:63}, derived by H.H.
Swope after W. Baade's death from his $200''$-plates 
and from H.\,C. Arp's photoelectric sequence, may be considered as the
beginning of a new era. (For the history of the time cf.\ also
\citealt{Sandage:98,Sandage:99a}).

   By the same time the ``direct'' (i.e.\ non-spectroscopic) staff
members at the Mount Wilson and Palomar observatories (W. Baade,
E. Hubble, M. Humason, A. Sandage, and others) had accumulated many
$200''$-plates of a few galaxies outside the Local Group for work on
the Cepheids. In addition, A. Sandage had set up photoelectric
sequences around these galaxies, whose faintness and quality has
remained  unsurpassed until the advent of CCD detectors.

   Although the first Cepheid distance of NGC\,2403 to come out of
this program confirmed Sandage's \citeyear{Sandage:62} value
\citep{Tammann:Sandage:68}, using the then latest version of the
Cepheid period-luminosity (P-L) relation \citep{Sandage:Tammann:68},
it was criticized as being (much) too large
\citep[e.g.][]{Madore:76,deVaucouleurs:78,Hanes:82}. The modern value
is actually marginally larger \citep{Freedman:etal:01}.

   The second galaxy of the program, NGC\,5457 (M\,101), came as a
great surprise: its distance was found twice the value of Sandage's 
(\citeyear{Sandage:62}) estimate \citep{Sandage:Tammann:74a}, i.e.\
$(m-M)^{0}=29.3$. The distance of M\,101 and its companions was based on
brightest stars, HII region sizes, and van den Bergh's
(\citeyear{vandenBergh:60}) luminosity classes of spiral galaxies,
but also heavily on the {\em absence\/} of Cepheids down to the
detection limit. The faint Cepheids were eventually found with HST,
yielding  $(m-M)^{0}=29.34$ \citep{Kelson:etal:96}. In the mean time the
distance had been denounced as being too large
\citep[e.g.][]{deVaucouleurs:78,Humphreys:Strom:83}. 

   The new distance of M\,101 made clear that the brightest spirals of
luminosity class (LC)\,I  are brighter than anticipated and
that the luminosity of their brightest stars and the size of their
largest HII regions had to be increased. This led immediately to a
distance of the Virgo cluster of $(m-M)=31.45$
\citep{Sandage:Tammann:74b}, --- a value probably only slightly too
small \citep[cf.][]{Tammann:etal:01b}. The ensuing luminosity
calibration of LC\,I spirals could then be applied to a specially
selected, {\em distance-limited\/} sample of 36 such galaxies, bounded
by $8500\kms$. The conclusion was that $H_{0}=55\pm5$ ``everywhere''
\citep{Sandage:Tammann:75}. The largest contribution to the systematic
errors was attributed to the calibration through Cepheids (cf.\
Section~\ref{sec:09}). 

   The main antagonist of this solution became G. de
Vaucouleurs. Having started with $H_{0}=50$ from brightest globular
clusters \citep{deVaucouleurs:70}, he switched to $H_{0}\sim100\pm10$
\citep{deVaucouleurs:77,deVaucouleurs:Bollinger:79}. By assuming
rather short local distances and by turning a blind eye to all
selection effects, he managed to maintain this value --- eventually
with strong directional variations --- until his last paper on the
subject \citep{deVaucouleurs:Peters:85}.


   In the mean time new distance indicators were proposed which
correlate global galaxian observables with the total luminosity or
the diameter of a galaxy. An extrapolation of {\"O}pik's
(\citeyear{Oepik:21}) method was to use the 21cm HI-line width (a
measure of the rotational velocity) as a mass and hence luminosity
indicator, i.e.\ the so-called Tully-Fisher relation
\citep{Gouguenheim:69,Tully:Fisher:77,Sandage:Tammann:76}. It followed
the L-$\sigma$ \citep{Minkowski:62,Faber:Jackson:76}, D$_n$-$\sigma$
\citep{Dressler:etal:87}, or fundamental plane
\citep{Djorgovski:Davis:87} method and the surface brightness
fluctuation (SBF) method \citep{Tonry:Schneider:88}. Since these
relations have considerable intrinsic scatter their discussion is
deferred to Section~\ref{sec:07}.

   The turnover point of the bell-shaped luminosity function of
globular clusters has been used as a distance indicator
\citep*{vandenBergh:etal:85} . The successes and failures of the method
are discussed elsewhere \citep{Tammann:Sandage:99}.

   Following a proposal by \citet{Ford:Jenner:78} also brightest
planetary nebulae have been widely used as distance indicators. But
the method seems to depend on population size
\citep{Bottinelli:etal:91,Tammann:93}, chemical composition, and age
\citep{Mendez:etal:93}.

% **************************************************************
% 6. A New Complication: Peculiar Motions
% **************************************************************
\section{A Complication: Peculiar Motions}
\label{sec:06}
%
Peculiar motions, addressed already by \citet{deSitter:30}, may
camouflage the true value of $H_0$, the negative velocity of M\,31
being a clear warning. Moreover \citet{Zwicky:33} had pointed out the
enormous virial motions in high-density clusters. But in the 1930's
the one-dimensional peculiar motions of field galaxies were estimated
to be $\la200\kms$ \citep{Hubble:Humason:31,Hubble:Humason:34}. 
Later work has shown that they are rather $\la50\kms$ on average at a
local scale of $5\;$Mpc 
\citep{Yahil:etal:77,Sandage:86,Ekholm:etal:01,Karachentsev:etal:02}
or even of $10\;$Mpc \citep{Tammann:Kraan-Korteweg:78}. Yet the size
of the peculiar motions increases with the scale length.

   The first physically motivated detection of a significant streaming
velocity, viz.\ towards the Virgo cluster center, is due to
Peebles (\citeyear{Peebles:76}; \citealt{Davis:Peebles:83}). 
Later work showed that the
Virgocentric flow amounts to $\sim\!220\pm50\kms$ at the position of the
Local Group \citep{Tammann:Sandage:85,Kraan-Korteweg:86}. Much larger
streaming velocities have since been proposed over still larger
scales, but it has never become clear, whether they are not due to Malmquist
bias of poorly defined galaxy samples (Section~\ref{sec:07}). 

   The total (three-dimensional) vector of $\sim\!630\kms$ of all
peculiar motions the Local Group partakes in, is reflected in the CMB
dipole \citep{Corey:Wilkinson:76, Smoot:etal:77}. A significant
fraction of the dipole is probably generated on scales within
$\la6000\kms$ \citep{Dale:etal:99,daCosta:etal:00}, although some
authors still favor higher values. As a consequence a reliable
large-scale value of $H_0$ should be determined at $>6000-10\,000\kms$
(Section~\ref{sec:08}).

   Notwithstanding the presence of large bulk motions the mean value
of $H_0$ turns out to be surprisingly scale-invariant. Within
$v\sim1200\kms$ (excluding the Virgo region) $H_0$ is only
insignificantly different from the large-scale value by $\Delta
H_{0}=1.8\pm2.7$ \citep[][Fig.~9]{Tammann:etal:01b}. Note that the
local and distant values of $H_0$ are about equally affected by any
errors of the underlying Cepheid calibration (cf.\ Section~\ref{sec:09}).


% **************************************************************
% 7. Yet Another Complication: Selection Bias
% **************************************************************
\section{Yet Another Problem: Selection Bias}
\label{sec:07}
%
The lesson of \citet{Malmquist:20} was only slowly incorporated by
extragalactic workers and is still not fully accounted for in some
modern work. The essence is that the mean luminosity of objects drawn
from an (apparent-) {\em magnitude-limited\/} sample increases with
distance, and that one overestimates $H_0$ as a consequence of this,
if one applies a local calibration to distant objects.

   The influence of the Malmquist bias was greatly exacerbated when
distance indicators came into use which use global galaxian
parameters as distance indicators, like the LC, TF, D$_{n}$-$\sigma$
(or fundamental-plane), or SBF methods. These methods have important
luminosity scatter in the order of $\sigma_{M}>0\fm3$, and since
the bias is strongly dependent on the size of the true intrinsic
scatter $\sigma_{M}$ (which is difficult to determine), they are
highly susceptible to Malmquist bias. Non-allowance for Malmquist bias
leads always, of course, to too high values of $H_0$.

   The literature abounds with $H_0$ determinations by means of the
above relations as applied to (complete or even incomplete) {\em
  magnitude-limited\/} samples. They typically lead to incorrect
values of $70 \la H_{0} \la 80$.

   The obvious way to overcome the Malmquist bias is to use {\em
distance-limited\/} samples. Examples are TF distances of a complete
galaxy sample bounded by $1000\kms$ (avoiding the wider Virgo region
as being too noisy for velocities to represent a good distance cutoff;
\citealt{Federspiel:99}; cf. \citealt{Tammann:etal:01b}, Fig.~5a) and
giving $H_{0}=59\pm3$, or a complete sample of Virgo cluster spirals
yielding a TF modulus of $(m-M)_{\rm Virgo}=31.58\pm0.24$
\citep{Federspiel:99}. 

   But complete distance- or volume-limited samples are restricted to
quite local regions. Several authors have therefore developed various
methods how to derive unbiased values of $H_0$ from (complete)
magnitude-limited samples of field galaxies
(\citealt{Teerikorpi:84,Teerikorpi:97,Bottinelli:etal:86};
\citealt*{Federspiel:etal:94}; 
for a tutorial see \citealt{Sandage:95}; for a parameter-free method
see \citealt{Hendry:02}). Also cluster samples are affected by
Teerikorpi Cluster Population Incompleteness Bias
\citep*{Teerikorpi:87,Sandage:etal:95}. The original hope that the
inverse TF relation was bias-free has not substantiated
\citep{Teerikorpi:etal:99}. 

   Bias-corrected samples of field galaxies give typical values of
$H_{0}\la60$, e.g. from LC
\citep{Sandage:96,Sandage:99b,Sandage:02,Paturel:etal:98}, from TF
\citep{Theureau:etal:97,Theureau:00,Ekholm:etal:99,Hendry:02}, from
galaxy diameters \citep{Goodwin:etal:97}, and from the
D$_{n}$-$\sigma$ method \citep{Federspiel:99}.

   All these solutions reach hardly beyond $5000\kms$, even in the
best cases. The determination of the large-scale value of $H_0$ is
therefore deferred to the next Section.

% **************************************************************
% 8. The Golden Route to the Large-Scale Value of Ho
% **************************************************************
\section{The Golden Route to the Large-Scale Value of \boldmath{$H_0$}}
\label{sec:08}
%
Two developments have opened a simple and reliable way for the
determination of $H_0$ out to distances of $\sim\!30\,000\kms$.

\noindent
1) Following an early suggestion by \citet{Kowal:68} it has become
increasingly clear that SNe\,Ia are the most powerful standard
candles to date. The scatter of their Hubble diagram decreased
steadily as it became possible: a) to remove non-type Ia SNe from the
sample, b) to obtain good photometry of their magnitudes at maximum,
many of which are due to a specific program at Cerro Tololo, c) to
allow for the dependence of $m_{\max}$ on the decline rate of the
light curve, --- a correction which turned out to be smaller than
originally proposed by \citet{Phillips:93}, and d) to correct for a
dependence of $m_{\max}$ on the intrinsic color of the SN\,Ia
\citep{Tammann:Sandage:95,Tripp:98}. \citet{Parodi:etal:00} have
compiled a complete fiducial sample of 35 blue SNe\,Ia, which fulfill
the conditions $(B\!-\!V)^0 \le 0.10$ and
$1200<v<30\,000\kms$ (the lower limit is imposed to reduce the effect
of peculiar velocities, the upper limit is to minimize the effect of
$\Omega_{\rm M}$ and $\Omega_{\Lambda}$). This sample allows to
determine good dependencies of $m_{\max}$ on decline rate and
intrinsic color. The resulting $m_{\max}^{\rm corr}$ in $B$, $V$, and
$I$ define very tight Hubble diagrams
\citep[cf.][]{Parodi:etal:00}. As an example only the Hubble diagram
in $V$ is shown here (Fig.~\ref{fig:hub:sneia}). % --- 
The solution for the Hubble line, shown in the Figure, excludes the
nine SNe\,Ia which have a Galactic absorption of $A_{V}>0\fm2$
according to \citet{Schlegel:etal:98}.  They appear to be somewhat
bright and their absorption may be overestimated.
% **************************************************************
%  Figure 1: Hubble diagram SNeIa in V of the fiducial sample (n=26) 
%            -> snfs_A.eps from sn_huba.pro
% **************************************************************
\def\floatwidth{0.7\textwidth} 
\begin{figure}[t] 
\centerline{\includegraphics[width=\floatwidth]{tammann1.eps}} 
\caption{The Hubble diagram in $V$ for the 35 
  SNe\,Ia of the fiducial sample with magnitudes $m^{\rm corr}_V$, 
  i.e. corrected for decline rate $\Delta m_{15}$ and color $(B-V)$. 
   The solid line is a fit to the 26 SNe\,Ia with 
  $A_V\le0\fm2$ (closed circles) 
  assuming a flat universe with $\Omega_{\rm M}=0.3$ and 
  $\Omega_{\Lambda}=0.7$; the dashed line is a linear fit with a
  forced   slope of 0.2 (corresponding approximately to $\Omega_{\rm
  M}=1.0$ and $\Omega_{\Lambda}=0.0$).} 
\label{fig:hub:sneia}
\end{figure}
% **************************************************************

   The very small scatter of $\sigma_{m}=0\fm12$ in
Fig.~\ref{fig:hub:sneia} could be entirely due to observational errors
(in magnitude and color), to which peculiar velocities may contribute
to some extent. The luminosity variation of homogenized, blue SNe\,Ia
is therefore below the detection limit. Their unique r{\^o}le as
standard candles and their insensitivity against Malmquist bias are
unquestionable. 

   The conclusion is that SNe\,Ia open the golden route to the
large-scale value of $H_0$ if ``only'' their absolute magnitude
$M^{\rm corr}$ can be determined. 

\noindent
2) The advent of HST made it possible --- as a pilot program had shown
\citep{Sandage:Tammann:82} --- that the required luminosity
calibration of SNe\,Ia could be achieved. A special HST program was
mounted with the aim of determining Cepheid distances of {\em
  nearby\/} galaxies which have produced a well observed SN\,Ia in
the past. This has now led to the distances of seven standard SNe\,Ia,
which were  augmented by two additional objects from external
sources. The data are compiled in \citet{Saha:etal:01}. The mean
absolute magnitude of the nine SNe\,Ia, after correction for decline
rate and color, becomes $M_{V}^{\rm corr}=-19.53\pm0.06$. 

   If this value is combined with the equation of the corresponding
Hubble line, as shown at the bottom of Fig.~\ref{fig:hub:sneia},
one obtains 
\begin{equation}\label{eq:h0}
   H_{0} = 56.9\pm2.3.
\end{equation}
Very similar solutions are obtained from the $B$ and $I$ magnitudes
\citep[cf.][]{Tammann:etal:01b}. The value of $H_0$ could be increased
by 1.6 units if the LMC distance modulus, i.e.\ the zero point of the
Cepheid distance scale, were adopted to be 18.50, instead of 18.56
used here. It could also be increased by 1.3 units if all 35 SNe\,Ia
were included in the solution. $H_0$ decreases by 0.8 units for an
$\Omega_{\rm M}=1$, $\Omega_{\Lambda}=0$ Universe. (Note the
  non-vanishing effect which $\Lambda$ has already at
  $v=30\,000\kms$).

   An important feature of the present solution is that the
calibrating SNe\,Ia and the distant sample of SNe\,Ia have the same
absorption-corrected mean colors. Solutions which do not fulfill this
condition betray an inconsistent treatment of the two sets.

   Equation~(\ref{eq:h0}) reflects only statistical errors. The
systematic errors are discussed by \citet{Saha:etal:01} and
\citet{Tammann:etal:01b}. The conclusion is that the systematic error
of $H_0$ is $\la10\%$, the slope of the magnitude dependence on
decline rate and color contributing somewhat, but the main source of
error being the Cepheid distances discussed in the next Section. 

   A note is here in place on the equally tight Hubble diagram from
relative TF distances of clusters (\citealt{Giovanelli:etal:97};
\citealt{Dale:etal:99}; cf. \citealt{Tammann:etal:01a}, Fig.~2),
where the cluster distances are based on the mean of about 15
subjectively selected spirals per cluster. The formidable problem is,
however, how to calibrate the diagram. One possibility is to {\em
  adopt\/} the distance of one or more clusters. 
\citet{Sakai:etal:00} have applied instead the local calibration of
the TF relation (derived from known Cepheid distances) directly to the
individual cluster galaxies, and have obtained a value of $H_{0}=71$. 
This procedure is of course invalid. It is well known that if one
applies the TF calibration to only some bright members of the Virgo
cluster or any other cluster, the mean distance 
becomes $\sim\!0\fm4$ smaller than from the complete cluster spiral
population \citep[Fig.~6]{Kraan-Korteweg:etal:88}.
This is a typical example of the Teerikorpi Cluster Bias effect (cf.\
Section~\ref{sec:07}). It is therefore obvious that the value of $H_0$
by \citeauthor{Sakai:etal:00} must be too high by roughly $20\%$.

   The same objection holds against the calibration of the Hubble
diagram of 11 clusters, whose relative distances are based on the mean
D$_n-\sigma$ distances of a few cluster E/S0 members
\citep{Kelson:etal:00}. The additional problem is here that even the
local calibration of the D$_n-\sigma$ relation is shaky because there
is no early-type galaxy with a primary distance determination.

   Purely physical methods leading directly to $H_0$, without using
any astronomical distance for calibration, are steadily gaining
weight. A combined solution of six gravitationally lensed double or
multiple quasars yields for a $\Lambda$CDM model a well constrained
value of $50<H_{0}<60$ \citep{Saha:02}. The physics of the light curve
plateau of SNe of type IIP suggests values of $54\la H_{0}\la65$
\citep{Hamuy:01,Nadyozhin:02}. \citet{Lasenby:02}, summarizing the
data from the Sunyaev-Zeldovich effect, concludes that $H_0$ is
``sixtyish''. CMB fluctuations are compatible with the same estimate
\citep{Netterfield:etal:02,Pryke:02}, but instead of determing $H_0$
from the CMB it should rather be used as a prior to confine other
parameters of the early Universe \citep{Durrer:02}. This is in fact
the main motivation at present to determine as precise a
CMB-independent value of $H_0$ as possible.


% **************************************************************
% 9. Back to the Beginnings
% **************************************************************
\section{Back to the Beginnings}
\label{sec:09}
%
It was suggested \citep{Freedman:etal:01} that the absorption of LMC
Cepheids, widely used as zero point for all Cepheid distances, had
been overestimated so far and that Cepheids were intrinsically dimmer
than anticipated; this would result in an {\em increase\/} of $H_0$ by
$\sim\!6\%$. This suggestion is not correct for long-period Cepheids
\citep{Tammann:etal:01b}, which are decisive for the luminosity
calibration of SNe\,Ia, but the suggestion invited a closer look into
the P-L and P-C relations of Cepheids in different galaxies.

   The data for nearby Cepheids have dramatically increased in recent
years. \citet{Berdnikov:etal:00} have provided $B,V,I$ photometry for
hundreds of Galactic Cepheids for which \citet{Fernie:etal:95} have
determined reddening values. \citet{Feast:99} has compiled the
distances of 28 Cepheids in Galactic clusters, and
\citet{Gieren:etal:98} have determined distances of 34 Galactic
Cepheids by means of the Baade-Becker-Wesselink
method. \citet{Udalski:etal:99a,Udalski:etal:99b} have published
periods and magnitudes in the standard system, obtained in the course
of the OGLE program, for many hundreds of fundamental-mode Cepheids in
LMC and SMC as well as their consistent $E(B\!-\!V)$ values.
% **************************************************************
%  Figure 2: The mean position in the two-color diagram (B-V) vs (V-I) 
%            -> ud_2col.eps from ud_2col.pro
% **************************************************************
\def\floatwidth{0.64\textwidth}
\begin{figure}[tb]
\centerline{\includegraphics[width=\floatwidth]{tammann2.eps}}
\caption{The mean position in the two-color diagram [$(B\!-\!V)^0$
  versus $(V\!-\!I)^0$] of Galactic, LMC, and SMC Cepheids. The loci
  of different values of $\log P$ are indicated.} 
\label{fig:2color}
\end{figure}
% **************************************************************

   The analysis of this wealth of data is still in progress, but it is
already clear that the P-L and P-C relations are different in
different galaxies. In LMC neither the P-L nor the P-C relation can be
fitted by a single slope \citep{Tammann:etal:01b}, whereas the steep
Galactic P-L relation shows no deviation from linearity. 
Cepheids in LMC are up to $0\fm5$
brighter at $\log P = 0.4$ than their Galactic counterparts (somewhat
dependent on the adopted distances), but the difference diminishes
towards longer periods. It is a lucky coincidence that the Galactic
and LMC P-L relations cross at $\log P \approx 1.5$ and that this is
about the median period of the SNe\,Ia-calibrating Cepheids. But the
choice of any specific P-L relation may influence the resulting
absorption-corrected distance of external galaxies by up to $10\%$. 

   A distance-independent comparison of the Cepheids in the Galaxy,
LMC, and SMC is afforded by their mean position in the color-color
diagram (Fig.~\ref{fig:2color}). It cannot entirely be excluded that the
(large) Galactic $E(B\!-\!V)$ values are underestimated and that the
Galactic Cepheids should be slid closer to the LMC Cepheids along the
reddening line, but the fact that Cepheids in SMC at a given period
are bluer in $(B\!-\!V)^0$ and redder in $(V\!-\!I)^0$ than those in
LMC cannot be the result of incorrect reddenings. If the P-C relations
are not universal then it follows by necessity that also the P-L
relations must be different, at least at some wavelengths.

   It comes as a surprise that the largest single source of systematic
errors, which affect the luminosity calibration of SNe\,Ia and hence
the large-scale value of $H_0$, is due to the intrinsic difference of
Cepheids in different galaxies. {\em Of course, all other distance
determinations which are calibrated through Cepheids face the same
problem}. At present it is not known which parameter decides on the
specific form of the P-L relation, but metallicity is a prime
suspect. If this is so, and considering that the mean metallicity of
the SNe\,Ia-calibrating galaxies is roughly $\mbox{[Fe/H]}=0$, one
should prefer the Galactic over the LMC P-L relation. In that case the
galaxy distances, based on long-period Cepheids, would tend to
increase.

   It is a long-range program of the future to trace accurate P-C and
calibrated P-L relations in a variety of nearby galaxies, to understand
the physics of their being different, and then to decide about their
applicability to more distant galaxies. It may take the astrometric
distances from GAIA to calibrate the various P-L relations for further
use as distance indicators. At present it is prudent to attribute a
systematic error of at least $5\%$ to the value of $H_0$, accounting
for only the intrinsic difference of Cepheids.


% **************************************************************
%  Acknowledgments
% **************************************************************
\section*{Acknowledgments}
%
The authors thank Dr.~A.~Sandage for the permission to use his
manuscript on the history of the Mount Wilson Observatory. They thank
the Swiss National Science Foundation for financial support.

% **************************************************************
% Bibliography
% **************************************************************
\begin{thebibliography}{}
% **************************************************************
%  number-superscript(?)
% **************************************************************
% \begin{thebibliography}{999}
%
\bibitem[Baade(1944)]{Baade:44}
   Baade, W. 1944,
   {\em ApJ} {\bf 100}, 137.
%
\bibitem[Baade(1952)]{Baade:52}
   Baade, W. 1952,
   {\em I.A.U. Trans.} VIII (Cambridge: Cambridge Univ. Press), p. 397.
%
\bibitem[Baade(1963)]{Baade:63}
   Baade, W. 1963,
   {\em Evolution of Stars and Galaxies}, ed. C. Payne-Gaposchkin,
   (Cambridge, Mass.: Harvard Univ. Press), p.~28. 
%
\bibitem[Baade \& Swope(1954)]{Baade:Swope:54}
   Baade, W., \& Swope, H.H. 1954,
   {\em Yearbook Carnegie Inst.} {\bf 53}, 20.
%
\bibitem[Baade \& Swope(1963)]{Baade:Swope:63}
   Baade, W., \& Swope, H.H. 1963,
   % Variable star field 96' south preceeding the nucleous oftheAnd
   % galaxy. 
   {\em AJ} {\bf 68}, 435.
%
\bibitem[Behr(1951)]{Behr:51}
   Behr, A. 1951,
   % Zur Entfernungsskala der extragalaktischen Nebel
   {\em A.N.} {\bf 279}, 97.
%
\bibitem[Berdnikov et~al.(2000)Berdnikov, Dambis, \&
   Voziakova]{Berdnikov:etal:00} 
   Berdnikov, L.N., Dambis, A.K., \& Voziakova, O.V., 2000,
   % Galactic Cepheids. Catalogue of light-curve parameters and
   % distances 
   {\em A\&AS} {\bf 143}, 211.
%
\bibitem[Bottinelli et~al.(1986)]{Bottinelli:etal:86}
   Bottinelli, L., Gouguenheim, L., Paturel, G., \& Teerikorpi,
   P. 1986,
   % The Malmquist bias and the value of H0 from the Tully-Fisher
   % relation 
   {\em A\&A} {\bf 156}, 157.
%
\bibitem[Bottinelli et~al.(1991)]{Bottinelli:etal:91}
   Bottinelli, L., Gouguenheim, L., Paturel, G., \& Teerikorpi,
   P. 1991,
   % A systematic effect in the use of planetary nebulae as standard
   % candles 
   {\em A\&A} {\bf 252}, 550.
%
\bibitem[Corey \& Wilkinson(1976)]{Corey:Wilkinson:76}
   Corey, B.E., \& Wilkinson, D.T. 1976,
   {\em BAAS} {\bf 8}, 351.
%
\bibitem[da Costa et~al.(2000)]{daCosta:etal:00}
   da Costa, L.N., et~al. 2000,
   % Redshift-Distance Survey of Early-Type Galaxies: Dipole of the
   % Velocity Field 
   {\em ApJ} {\bf 537}, L81.
%
\bibitem[Dale et~al.(1999)]{Dale:etal:99}
   Dale, D.A., Giovanelli, R., Haynes, M.P., Campusano, L.E., \&
   Hardy, E. 1999,
   % Seeking the Local Convergence Depth. V. Tully-Fisher Peculiar
   % Velocities for 52 Abell Clusters 
   {\em AJ} {\bf 118}, 1489.
%
\bibitem[Davis \& Peebles(1983)]{Davis:Peebles:83}
   Davis, M., \& Peebles, P.J.E. 1983,
   % Evidence for local anisotropy of the Hubble flow
   {\em ARA\&A} {\bf 21}, 109.
%
\bibitem[de Sitter(1916)]{deSitter:16}
   de Sitter, W. 1916,
   % Einstein's theory of gravitation and its astronomical consequences
   {\em MNRAS} {\bf 76}, 699.
%
\bibitem[de Sitter(1917)]{deSitter:17}
   de Sitter, W. 1917,
   % Einstein's theory of gravitation and its astronomical
   % consequences. Third paper 
   {\em MNRAS} {\bf 78}, 3.
%
\bibitem[de Sitter(1930)]{deSitter:30}
   de Sitter, W. 1930,
   % On the magnitudes, diameters and distances of the extragalactic
   % nebulae and their apparent radial velocities (Errata: 5 V, 230) 
   {\em BAN} {\bf 5}, 157.
%
\bibitem[de Vaucouleurs(1970)]{deVaucouleurs:70}
   de Vaucouleurs, G. 1970,
   % The Brightest Star Clusters in Galaxies as Distance Indicators 
   {\em ApJ} {\bf 159}, 435.
%
\bibitem[de Vaucouleurs(1977)]{deVaucouleurs:77}
   de Vaucouleurs, G. 1977,
   % Distances de Groupes et Amas Proches et la Valeur Locale DU
   % Rapport de Hubble 
   in: {\em D{\'e}calage vers le rouge et expansion de l'univers},
   eds. C. Balkowski \&  B.E. Westerlund, IAU Coll. {\bf 37}, (Paris:
   Ed. CNRS), p.~301. 
%
\bibitem[de Vaucouleurs(1978)]{deVaucouleurs:78}
   de Vaucouleurs, G. 1978,
   % The extragalactic distance scale. IV - Distances of nearest
   % groups and field galaxies from secondary indicators 
   {\em ApJ} {\bf 224}, 710.
%
\bibitem[de Vaucouleurs \& Bollinger(1979)]{deVaucouleurs:Bollinger:79}
   de Vaucouleurs, G., \& Bollinger, G. 1979,
   % The extragalactic distance scale. VII - The velocity-distance
   % relations in different directions and the Hubble ratio within and
   % without the local supercluster 
   {\em ApJ} {\bf 233}, 433.
%
\bibitem[de Vaucouleurs \& Peters(1985)]{deVaucouleurs:Peters:85}
   de Vaucouleurs, G., \& Peters, W. 1985,
   % A preliminary mapping of the extragalactic velocity field near
   % the plane of the local supercluster 
   {\em ApJ} {\bf 297}, 27.
%
\bibitem[Djorgovski \& Davis(1987)]{Djorgovski:Davis:87}
   Djorgovski, S., \& Davis, M. 1987,
   % Fundamental properties of elliptical galaxies
   {\em ApJ} {\bf 313}, 59.
%
\bibitem[Dressler et~al.(1987)]{Dressler:etal:87}
   Dressler, A., Faber, S.M., Burstein, D., Davies, R.L., Lynden-Bell,
   D., Terlevich, R.J., \& Wegner, G. 1987,
   % Spectroscopy and photometry of elliptical galaxies - A
   % large-scale streaming motion in the local universe 
   {\em ApJ} {\bf 313}, L37.
%
\bibitem[Durrer(2002)]{Durrer:02}
   Durrer, R. 2002,
   in: {\em Matter in the Universe}, eds. Ph. Jetzer, K. Pretzl, \&
   R. von Steiger, (Dordrecht: Kluwer), p.~3.
%
\bibitem[Ekholm et~al.(1999)]{Ekholm:etal:99}
   Ekholm, T., Teerikorpi, P., Theureau, G., Hanski, M., Paturel, G.,
   Bottinelli, L., \& Gouguenheim, L. 1999,
   % Kinematics of the local Universe. X. H_0 from the inverse B-band
   % Tully-Fisher relation using diameter and magnitude limited samples 
   {\em A\&A} {\bf 347}, 99.
%
\bibitem[Ekholm et~al.(2001)]{Ekholm:etal:01}
   Ekholm, T., Baryshev, Y., Teerikorpi, P., Hanski, M., \&  Paturel,
   G. 2001,
   % On the quiescence of the Hubble flow in the vicinity of the Local
   % Group. A study using galaxies with distances from the Cepheid
   % PL-relation 
   A\&A {\bf 368}, 17.
%
\bibitem[Faber \& Jackson(1976)]{Faber:Jackson:76}
   Faber, S.M., \& Jackson, R.E. 1976,
   % Velocity dispersions and mass-to-light ratios for elliptical
   % galaxies 
   {\em ApJ} {\bf 204}, 668.
%
\bibitem[Feast(1999)]{Feast:99}
   Feast, M.W. 1999,
   % Cepheids as Distance Indicators
   {\em PASP} {\bf 111}, 775.
%
\bibitem[Federspiel(1999)]{Federspiel:99}
   Federspiel, M. 1999,
   Ph.D. Thesis, Univ. Basel.
%
\bibitem[Federspiel et~al.(1994)Federspiel, Sandage, \&
Tammann]{Federspiel:etal:94} 
   Federspiel, M., Sandage, A., \& Tammann, G.A. 1994,
   % Bias properties of extragalactic distance indicators. 3: Analysis
   % of Tully-Fisher distances for the Mathewson-Ford-Buchhorn sample
   % of 1355 galaxies 
   {\em ApJ} {\bf 430}, 29.
%
\bibitem[Fernie(1970)]{Fernie:70}
   Fernie, J.D. 1995,
   %  The Historical Quest for the Nature of the Spiral Nebulae
   {\em PASP} {\bf 82}, 1189.
%
\bibitem[Fernie et~al.(1995)]{Fernie:etal:95}
   Fernie, J.D., Beattie, B., Evans, N.R., \& Seager, S. 1995,
   %  A Database of Galactic Classical Cepheids
   {\em IBVS} {\bf 4148}. 
%
\bibitem[Ford \& Jenner(1978)]{Ford:Jenner:78}
   Ford, H.C., \& Jenner, D.C. 1978,
   % Planetary Nebulae in the Nuclear Bulge of M81: A New Distance
   % Determination 
   {\em BAAS} {\bf 10}, 665.
%
\bibitem[Freedman et~al.(2001)]{Freedman:etal:01}
   Freedman, W.L., et~al. 2001,
   % Final Results from the Hubble Space Telescope Key Project to
   % Measure the Hubble Constant 
   {\em ApJ} {\bf 553}, 47.
%
\bibitem[Gieren et~al.(1998)Gieren, Fouqu{\'e}, \& Gomez]{Gieren:etal:98}
   Gieren, W.P., Fouqu{\'e}, P., \& Gomez, M. 1998,
   %  Cepheid Period-Radius and Period-Luminosity Relations and the
   %  Distance to the Large Magellanic Cloud 
   {\em ApJ} {\bf 496}, 17.
%
\bibitem[Giovanelli et~al.(1997)]{Giovanelli:etal:97}
   Giovanelli, R., et~al. 1997,
   %  The I band Tully-Fisher relation for cluster galaxies: data
   % presentation.  
   {\em AJ} {\bf 113}, 22.
%
\bibitem[Goodwin et~al.(1997)]{Goodwin:etal:97}
   Goodwin, S.P., Gribbin, J., \& Hendry, M.A. 1997,
   % A new Determination of the Hubble Parameter using Galaxy Linear
   % Diameters 
   {\em AJ} {\bf 114}, 2212.
%
\bibitem[Hamuy(2001)]{Hamuy:01}
   Hamuy, M.A. 2001,
   Ph.D. Thesis, Univ. of Arizona.
%
\bibitem[Gouguenheim(1969)]{Gouguenheim:69}
   Gouguenheim, L. 1969,
   % Neutral hydrogen content of small galaxies
   {\em A\&A} {\bf 3}, 281 (eq. 11c).
%
\bibitem[Hanes(1982)]{Hanes:82}
   Hanes, D.A. 1982,
   % A re-examination of the Sandage-Tammann extragalactic distance
   % scale 
   {\em MNRAS} {\bf 201}, 145.
%
\bibitem[Hendry(2002)]{Hendry:02}
   Hendry, M. 2002,
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., in press.
%
\bibitem[Hertzsprung(1914)]{Hertzsprung:14}
   Hertzsprung, E. 1913,
   % Ueber die raeumliche Verteilung der Veraenderlichen vom d
   % Cephei-Typus 
   {\em A.N.} {\bf 196}, 201.
%
\bibitem[Holmberg(1958)]{Holmberg:58}
   Holmberg, E. 1958,
   % A photographic photometry of extragalactic nebulae
   {\em Medd. Lunds Astr. Obs.} {\bf 2}, No.\,136.
%
\bibitem[Hubble(1925)]{Hubble:25}
   Hubble, E. 1925,
   % NGC 6822, a remote stellar system
   {\em ApJ} {\bf 62}, 409.
%
\bibitem[Hubble(1926)]{Hubble:26}
   Hubble, E. 1926,
   % A spiral nebula as a stellar system: Messier 33
   {\em ApJ} {\bf 63}, 236.
%
\bibitem[Hubble(1929a)]{Hubble:29a}
   Hubble, E. 1929a,
   % A spiral nebula as a stellar system, Messier 31
   {\em ApJ} {\bf 69}, 103.
%
\bibitem[Hubble(1929b)]{Hubble:29b}
   Hubble, E. 1929b,
   {\em Proc. Nat. Acad. Sci.} {\bf 15}, 168.
%
\bibitem[Hubble(1936a)]{Hubble:36a}
   Hubble, E. 1936a,
   {\em The Realm of Nebulae} (New Haven: Yale Univ. Press).
%
\bibitem[Hubble(1936b)]{Hubble:36b}
   Hubble, E. 1936b,
   % Effects of Red Shifts on the Distribution of Nebulae
   {\em ApJ} {\bf 84}, 517.
%
\bibitem[Hubble(1953)]{Hubble:53}
   Hubble, E. 1953,
   % The law of red shifts (George Darwin Lecture)
   {\em MNRAS} {\bf 113}, 658.
%
\bibitem[Hubble \& Humason(1931)]{Hubble:Humason:31}
   Hubble, E., \& Humason, M.L. 1931,
   % The Velocity-Distance Relation among Extra-Galactic Nebulae
   {\em ApJ} {\bf 74}, 43.
%
\bibitem[Hubble \& Humason(1934)]{Hubble:Humason:34}
   Hubble, E., \& Humason, M.L. 1934,
   % The Velocity-distance Relation for Isolated Extragalactic Nebulae 
   {\em Proc. Nat. Acad. Sci. USA} {\bf 20}, 264.
%
\bibitem[Humason(1936)]{Humason:36}
   Humason, M.L. 1936,
   % The Apparent Radial Velocities of 100 Extra-Galactic Nebulae
   {\em ApJ} {\bf 83}, 10.
%
\bibitem[HMS(1956)Humason, Mayall, \& Sandage]{Humason:etal:56}
   Humason, M.L., Mayall, N.U., \& Sandage, A.R. 1956,
   % Redshifts and magnitudes of extragalactic nebulae
   {\em AJ} {\bf 61}, 97 (HMS).
%
\bibitem[Humphreys \& Strom(1983)]{Humphreys:Strom:83}
   Humphreys, R.M., \& Strom, S.E. 1983,
   % M supergiants and the distance to M101
   {\em ApJ} {\bf 264}, 458.
%
\bibitem[Karachentsev et~al.(2002)]{Karachentsev:etal:02}
   Karachentsev, et~al. 2002,
   % The very local Hubble flow
   {\em A\&A} {\bf 389}, 812.
%
\bibitem[Kelson et~al.(1996)]{Kelson:etal:96}
   Kelson, et~al. 1996,
   % The Extragalactic Distance Scale Key Project. III. The Discovery
   % of Cepheids and a New Distance to M101 Using the Hubble Space
   % Telescope 
   {\em ApJ} {\bf 463}, 26.
%
\bibitem[Kelson et~al.(2000)]{Kelson:etal:00}
   Kelson, et~al. 2000,
   % The Hubble Space Telescope Key Project on the Extragalactic
   % Distance Scale. XXVII. A Derivation of the Hubble Constant Using
   % the Fundamental Plane and Dn-s Relations in Leo I, Virgo, and
   % Fornax 
   {\em ApJ} {\bf 529}, 768.
%
\bibitem[Kowal(1968)]{Kowal:68}
   Kowal, C.T. 1968,
   % Absolute magnitudes of supernovae 
   {\em AJ} {\bf 73}, 1021.
%
\bibitem[Kraan-Korteweg(1986)]{Kraan-Korteweg:86}
   Kraan-Korteweg, R.C. 1986,
   % A catalog of 2810 nearby galaxies - The effect of the
   % Virgocentric flow model on their observed velocities 
   {\em A\&AS} {\bf 66}, 255.
%
\bibitem[Kraan-Korteweg, Cameron, \& Tammann(1988)]{Kraan-Korteweg:etal:88}
   Kraan-Korteweg, R.C., Cameron, L.M., \& Tammann, G.A. 1988,
   % 21 centimeter line width distances of cluster galaxies and the
   % value of Ho 
   {\em ApJ} {\bf 331}, 620.
%
\bibitem[Lasenby(2002)]{Lasenby:02}
   Lasenby, A. 2002,
   Talk presented at a Coll., Basel 26.06.2002.
%
\bibitem[Lema{\^i}tre(1927)]{Lemaitre:27}
   Lema{\^i}tre, G. 1927,
   {\em Ann. Soc. Sci. Bruxelles} {\bf 47}, 49. (English translation
   in {\em MNRAS} {\bf 91}, 483 [1931]).
%
\bibitem[Lundmark(1920)]{Lundmark:20}
   Lundmark, K. 1920,
   {\em The relation of the globular clusters and spiral nebulae to
   the stellar system},
   (Stockholm: Handlingar).
%
\bibitem[Lundmark(1925)]{Lundmark:25}
   Lundmark, K. 1925,
   % Nebulae, The motions and the distances of spiral
   {\em MNRAS} {\bf 85}, 865.
%
\bibitem[Madore(1976)]{Madore:76}
   Madore, B.F. 1976,
   % The distance to NGC 2403
   {\em MNRAS} {\bf 177}, 157.
%
\bibitem[Malmquist(1920)]{Malmquist:20}
   Malmquist, G. 1920,
   {\em Medd. Lunds Astr. Obs.} {\bf 2}, No.\,22.
%
\bibitem[M{\'e}ndez et~al.(1993)]{Mendez:etal:93}
   M{\'e}ndez, R.H., Kudritzki, R.P.,  Ciardullo, R., \&  Jacoby, G.H.  1993,
   % The bright end of the planetary nebula luminosity function 
   {\em A\&A} {\bf 275}, 534.
%
\bibitem[Minkowski(1962)]{Minkowski:62}
   Minkowski 1962,
   % Internal Dispersion of Velocities in Other Galaxies
   in: {\em Problems of Extra-Galactic Research}, ed. G.C. McVittie,
   IAU Symp. {\bf 15}, (New York: Macmillan), p.~112.
   % oder: Identification with Optical Objects, p.~201
%
\bibitem[Mineur(1945)]{Mineur:45}
   Mineur, H. 1945,
   {\em C.\,R. Acad. Sci. Paris} {\bf 220}, 445.
%
\bibitem[Nadyozhin(2002)]{Nadyozhin:02}
   Nadyozhin, D.K., 2002,
   in: {\em From Twilight to Highlight, the Physics of Supernovae},
   ESO/MPA/MPE Workshop, in press.
%
\bibitem[Netterfield et~al.(2002)]{Netterfield:etal:02}
   Netterfield, C.B., et~al. 2002,
   % A Measurement by BOOMERANG of Multiple Peaks in the Angular Power
   % Spectrum of the Cosmic Microwave Background 
   {\em ApJ} {\bf 571}, 604.
%
\bibitem[{\"O}pik(1921)]{Oepik:21}
   {\"O}pik, E. 1921,
   {\em Weltkunde} (Russian) {\bf 10}, 12.
%
\bibitem[{\"O}pik(1922)]{Oepik:22}
   {\"O}pik, E. 1922,
   % An estimate of the distance of the Andromeda Nebula
   {\em ApJ} {\bf 55}, 406.
%
\bibitem[Parodi et~al.(2000)]{Parodi:etal:00}
   Parodi, B.R., Saha, A., Sandage, A., \& Tammann, G.A. 2000,
   % Supernova Type Ia Luminosities, Their Dependence on Second
   % Parameters, and the Value of Ho
   {\em ApJ} {\bf 540}, 634.
%
\bibitem[Paturel et~al.(1998)]{Paturel:etal:98}
   Paturel, G., et~al. 1998,
   % Hubble constant from sosie galaxies and HIPPARCOS geometrical
   % calibration 
   {\em A\&A} {\bf 339}, 671.
%
\bibitem[Peebles(1976)]{Peebles:76}
   Peebles, P.J.E. 1976,
   % The Peculiar Velocity Field in the Local Supercluster
   {\em ApJ} {\bf 205}, 318.
%
\bibitem[Phillips(1993)]{Phillips:93}
   Phillips, M.M. 1993,
   % The absolute magnitudes of Type IA supernovae
   {\em ApJ} {\bf 413}, L105.
%
\bibitem[Pryke(2002)]{Pryke:02}
   Pryke, C. 2002,
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., in press.
%
\bibitem[Ritchey(1917)]{Ritchey:17}
   Ritchey, G.W. 1917,
   % Novae in Spiral Nebulae
   {\em PASP} {\bf 29}, 207.
%
\bibitem[Robertson(1928)]{Robertson:28}
   Robertson, H.P. 1928,
   {\em Phil. Mag.} {\bf 5}, 835.
%
\bibitem[Saha et~al.(2001)]{Saha:etal:01}
   Saha, A., Sandage, A., Tammann, G.A., Dolphin, A.E., Christensen,
   J., Panagia, N., \& Macchetto, E.D. 2001,
   % Cepheid Calibration of the Peak Brightness of Type Ia
   % Supernovae. XI. SN 1998aq in NGC 3982 
   {\em ApJ} {\bf 562}, 314.
%
\bibitem[Saha(2002)]{Saha:02}
   Saha, P. 2002,
   Talk presented at a Coll., Basel 26.06.2002.
%
\bibitem[Sakai et~al.(2000)]{Sakai:etal:00}
   Sakai, et~al. 2000,
   % The Hubble Space Telescope Key Project on the Extragalactic
   % Distance Scale. XXIV. The Calibration of Tully-Fisher Relations and
   % the Value of the Hubble Constant 
   {\em ApJ} {\bf 529}, 698.
%
\bibitem[Sandage(1953)]{Sandage:53}
   Sandage, A. 1953,
   % The color-magnitude diagram for the globular cluster M3
   {\em AJ} {\bf 58}, 61.
%
\bibitem[Sandage(1954)]{Sandage:54}
   Sandage, A. 1954,
   % The first four years of extragalactic research with the Hale
   % 200-inch telescope 
   {\em AJ} {\bf 59}, 180.
%
\bibitem[Sandage(1958)]{Sandage:58}
   Sandage, A. 1958,
   % Current Problems in the Extragalactic Distance Scale
   {\em ApJ} {\bf 127}, 513.
%
\bibitem[Sandage(1962)]{Sandage:62}
   Sandage, A. 1962,
   % The Distance Scale
   in: {\em Problems of Extra-Galactic Research}, ed. G.C. McVittie,
   IAU Symp. {\bf 15}, (New York: Macmillan), p.~359.
%
\bibitem[Sandage(1972)]{Sandage:72}
   Sandage, A. 1972,
   % The redshift-distance relation. II. The Hubble diagram and its
   % scatter for first-ranked cluster galaxies: a formal value for qo 
   {\em ApJ} {\bf 178}, 1.
%
\bibitem[Sandage(1986)]{Sandage:86}
   Sandage, A. 1986,
   % The redshift-distance relation. IX - Perturbation of the very
   % nearby velocity field by the mass of the Local Group 
   {\em ApJ} {\bf 307}, 1.
%
\bibitem[Sandage(1995)]{Sandage:95}
   Sandage, A. 1995,
   in: {\em The Deep Universe}, 
   Saas-Fee Advanced Course {\bf 23}, 
   eds. B. Binggeli \& R. Buser, 
   (Berlin: Springer), p.~1.
%
\bibitem[Sandage(1996)]{Sandage:96}
   Sandage, A. 1996,
   % Bias Properties of Extragalactic Distance Indicators. V.Ho From
   % Luminosity Functions of Different Spiral Types and Luminosity
   % Classes Corrected for Bias 
   % 
   % Bias Properties of Extragalactic Distance
   % Indicators. VI. Luminosity Functions of M31 and M101 Look-alikes
   % Listed in the RSA2: Ho Therefrom 
   {\em AJ} {\bf 111}, 1 and 18.
%
\bibitem[Sandage(1998)]{Sandage:98}
   Sandage, A. 1998,
   % SN 1932 GAT: A Supernova of Unique Class
   in: {\em Supernovae and Cosmology}, 
   eds. L. Labhardt, B. Binggeli, \& R. Buser, 
   (Basel: Astron. Inst.), p.~201.
%
\bibitem[Sandage(1999a)]{Sandage:99a}
   Sandage, A. 1999a,
   % The First 50 Years at Palomar: 1949-1999 The Early Years of
   % Stellar Evolution, Cosmology, and High-Energy Astrophysics 
   {\em ARA\&A} {\bf 37}, 445.
%
\bibitem[Sandage(1999b)]{Sandage:99b}
   Sandage, A. 1999b,
   % Bias Properties of Extragalactic Distance Indicators. VIII. H0
   % from Distance-limited Luminosity Class and Morphological
   % Type-Specific Luminosity Functions for SB, SBC, and SC Galaxies
   % Calibrated Using Cepheids 
   {\em ApJ} {\bf 527}, 479.
%
\bibitem[Sandage(2002)]{Sandage:02}
   Sandage, A. 2002,
   % Bias Properties of Extragalactic Distance Indicators. X. The
   % Teerikorpi Cluster Population Incompleteness Bias for a Modified
   % Lema�tre-Robertson-Hubble-Humason Distance Method That Uses
   % Luminosity Functions 
   {\em AJ} {\bf 123}, 1179.
%
\bibitem[Sandage \& Hardy(1973)]{Sandage:Hardy:73}
   Sandage, A., \& Hardy, E. 1973,
   % The Redshift-Distance Relation. VIL Absolute Magnitudes of the
   % First Three Ranked Cluster Galaxies as Functions of Cluster
   % Richness and Bautz-Morgan Cluster Type: the Effect of qo 
   {\em ApJ} {\bf 183}, 743.
%
\bibitem[Sandage et~al.(1976)Sandage, Kristian, \& Westphal]{Sandage:etal:76}
   Sandage, A., Kristian, J., \& Westphal, J.A. 1976,
   % The extension of the Hubble diagram. I. New redshifts and BVR
   % photometry of remote cluster galaxies, and an improved richness
   % correction 
   {\em ApJ} {\bf 205}, 688.
%
\bibitem[Sandage \& Tammann(1968)]{Sandage:Tammann:68}
   Sandage, A., \& Tammann, G.A. 1968,
   % A Composite Period-Luminosity Relation for Cepheids at Mean and
   % Maximum Light 
   {\em ApJ} {\bf 151}, 531.
%
\bibitem[Sandage \& Tammann(1974a)]{Sandage:Tammann:74a}
   Sandage, A., \& Tammann, G.A. 1974a,
   % Steps toward the Hubble constant. III - The distance and stellar
   % content of the M101 group of galaxies 
   {\em ApJ} {\bf 194}, 223.
%
\bibitem[Sandage \& Tammann(1974b)]{Sandage:Tammann:74b}
   Sandage, A., \& Tammann, G.A. 1974b,
   % Steps toward the Hubble constant. IV - Distances to 39 galaxies
   % in the general field leading to a calibration of the galaxy
   % luminosity classes and a first hint of the value of Ho 
   {\em ApJ} {\bf 194}, 559.
%
\bibitem[Sandage \& Tammann(1975)]{Sandage:Tammann:75}
   Sandage, A., \& Tammann, G.A. 1975,
   % Steps toward the Hubble constant. VI - The Hubble constant
   % determined from redshifts and magnitudes of remote SC I galaxies:
   % The value of qo 
   {\em ApJ} {\bf 197}, 265.
%
\bibitem[Sandage \& Tammann(1976)]{Sandage:Tammann:76}
   Sandage, A., \& Tammann, G.A. 1976,
   % Steps toward the Hubble constant. VII - Distances to NGC 2403,
   % M101, and the Virgo cluster using 21 centimeter line widths
   % compared with optical methods: The global value of Ho 
   {\em ApJ} {\bf 210}, 7. 
%
\bibitem[Sandage \& Tammann(1982)]{Sandage:Tammann:82}
   Sandage, A., \& Tammann, G.A. 1982,
   % Steps toward the Hubble constant. VIII - The global value
   {\em ApJ} {\bf 256}, 339.
%
\bibitem[Sandage et~al.(1995)Sandage, Tammann, \&
Federspiel]{Sandage:etal:95} 
   Sandage, A., Tammann, G.A., \& Federspiel, M. 1995,
   % Bias Properties of Extragalactic Distance
   % Indicators. IV. Demonstration of the Population Incompleteness
   % Bias Inherent in the Tully-Fisher Method Applied to Clusters 
   {\em ApJ} {\bf 452}, 1.
%
\bibitem[Schlegel et~al.(1998)Schlegel, Finkbeiner, \& Davis]{Schlegel:etal:98}
   Schlegel, D., Finkbeiner, D., \& Davis, M. 1998,
   % Maps of Dust Infrared Emission for Use in Estimation of Reddening
   % and Cosmic Microwave Background Radiation Foregrounds 
   {\em ApJ} {\bf 500}, 525.
%
\bibitem[Shapley(1915)]{Shapley:15}
   Shapley, H. 1915,
   % Studies based on the colors and magnitudes in stellar
   % clusters. II. Thirteeen hundred stars in the Hercules Cluster
   % (Messier 13) 
   {\em Mt. Wilson Contrib.} {\bf 116}, 82.
%
\bibitem[Shapley(1918)]{Shapley:18}
   Shapley, H. 1918,
   % Studies based on the colors and magnitudes in stellar
   % clusters. VII. The distances, distribution in space, and dimensions
   % of 69 globular clusters 
   {\em ApJ} {\bf 48}, 154.
%
\bibitem[S{\'e}rsic(1960)]{Sersic:60}
   S{\'e}rsic, J.L. 1960,
   {\em Zs. f. Ap.} {\bf 50}, 168.
%
\bibitem[Slipher(1914)]{Slipher:14}
   Slipher, V.M. 1914,
   {\em Bulletin Lowell Obs.} {\bf 62}, 66.
%
\bibitem[Smoot, Gorenstein, \& Muller(1977)]{Smoot:etal:77}
   Smoot, G.F., Gorenstein, M.V., \& Muller, R.A. 1977, 
   % Detection of anisotropy in the cosmic blackbody radiation 
   {\em Phys. Rev. Lett.} {\bf 39}, 898.

%
\bibitem[Stebbins et~al.(1950)Stebbins, Whitford \& Johnson]{Stebbins:etal:50}
   Stebbins, J., Whitford, A.E., \& Johnson, H.L. 1950,
   % Photoelectric Magnitudes and Colors of Stars in Selected Areas
   % 57, 61, and 68 
   {\em ApJ} {\bf 112}, 469.
%
\bibitem[Stromberg(1925)]{Stromberg:25}
   Stromberg, G. 1925,
   % Analysis of radial velocities of globular clusters and
   % non-galactic nebulae
   {\em ApJ} {\bf 61}, 353.
%
\bibitem[Tammann(1993)]{Tammann:93}
   Tammann, G.A. 1993,
   % Why are Planetary Nebulae Poor Distance Indicators?
   in: {\em Planetary Nebulae}, eds. R. Weinberger \&  A. Acker,
   IAU Symp. {\bf 155}, p.~515.
%
\bibitem[Tammann \& Kraan-Korteweg(1978)]{Tammann:Kraan-Korteweg:78}
   Tammann, G.A., \& Kraan-Korteweg, R. 1978,
   % The galactic neighbourhood
   in: {\em Large Scale Structure of the Universe},
   eds. M.S. Longair \& J. Einasto, 
   IAU Symp. {\bf 79}, p.~71.
%
\bibitem[Tammann, Reindl, \& Thim(2001a)]{Tammann:etal:01a}
   Tammann, G.A., Reindl, B., \& Thim, F. 2001a,
   % Supernovae and the Large-Scale Value of Ho
   in: {\em Cosmology and Particle Physics}, eds. R. Durrer,
   J. Garcia-Bellido, \& M. Shaposhnikov, (Melville: Am. Inst. Phys.),
   p.~226. 
%
\bibitem[Tammann et~al.(2001b)]{Tammann:etal:01b}
   Tammann, G.A., Reindl, B., Thim, F., Saha, A., \& Sandage,
   A. 2001b,
   % Cepheids, Supernovae, Ho, and the Age of the Universe
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., astro-ph/0112489.
%
\bibitem[Tammann \& Sandage(1968)]{Tammann:Sandage:68}
   Tammann, G.A., \& Sandage, A. 1968,
   % The Stellar Content and Distance of the Galaxy NGC 2403 IN the
   % M81 Group 
   {\em ApJ} {\bf 151}, 825.
%
\bibitem[Tammann \& Sandage(1985)]{Tammann:Sandage:85}
   Tammann, G.A., \& Sandage, A. 1985,
   % The infall velocity toward Virgo, the Hubble constant, and a
   % search for motion toward the microwave background 
   {\em ApJ} {\bf 294}, 81.
%
\bibitem[Tammann \& Sandage(1995)]{Tammann:Sandage:95}
   Tammann, G.A., \& Sandage, A. 1995,
   % The Hubble Diagram for Supernovae of Type Ia. II. The Effect on
   % the Hubble Constant of a Correlation between Absolute Magnitude and
   % Light Decay Rate 
   {\em ApJ} {\bf 452}, 16.
%
\bibitem[Tammann \& Sandage(1999)]{Tammann:Sandage:99}
   Tammann, G.A., \& Sandage, A. 1999,
   % The Luminosity Function of Globular Clusters as an Extragalactic
   % Distance Indicator 
   in: {\em Harmonizing Cosmic Distance Scales in a Post-Hipparcos
   Era}, eds. D. Egret \& A. Heck, ASP Conf. Ser. {\bf 167}, p.~204.
%
\bibitem[Teerikorpi(1984)]{Teerikorpi:84}
   Teerikorpi, P. 1984,
   % Malmquist bias in a relation of the form M = AP + B
   {\em A\&A} {\bf 141}, 407.
%
\bibitem[Teerikorpi(1987)]{Teerikorpi:87}
   Teerikorpi, P. 1987,
   % Cluster population incompleteness bias and distances from the
   % Tully-Fisher relation - Theory and numerical examples 
   {\em A\&A} {\bf 173}, 39.
%
\bibitem[Teerikorpi(1997)]{Teerikorpi:97}
   Teerikorpi, P. 1997,
   % Observational Selection Bias Affecting the Determination of the
   % Extragalactic Distance Scale 
   {\em ARA\&A} {\bf 35}, 101.
%
\bibitem[Teerikorpi et~al.(1999)]{Teerikorpi:etal:99}
   Teerikorpi, P., Ekholm, T., Hanski, M.O., \& Theureau, G. 1999,
   % Theoretical aspects of the inverse Tully-Fisher relation as a
   % distance indicator: incompleteness in log {V_Max}, the relevant
   % slope, and the calibrator sample bias 
   {\em A\&A} {\bf 343}, 713.
%
\bibitem[Theureau et~al.(1997)]{Theureau:etal:97}
   Theureau, G., Hanski, M., Ekholm, T., Bottinelli, L., Gouguenheim,
   L., Paturel, G., \& Teerikorpi, P. 1997,
   % Kinematics of the Local Universe. V. The value of H_0_ from the
   % Tully-Fisher B and logD_25_ relations for field galaxies. 
   {\em A\&A} {\bf 322}, 730.
%
\bibitem[Theureau(2000)]{Theureau:00}
   Theureau, G. 2000,
   in: XIXth Texas Symposium, eds. E. Augbourg et~al., Mini-Symp. 13/12.
%
\bibitem[Tonry \& Schneider(1988)]{Tonry:Schneider:88}
   Tonry, J. \& Schneider, D.P. 1988,
   % A new technique for measuring extragalactic distances
   {\em AJ} {\bf 96}, 807.
%
\bibitem[Tripp(1998)]{Tripp:98}
   Tripp, R. 1998,
   % A two-parameter luminosity correction for Type IA supernovae
   {\em A\&A} {\bf 331}, 815.
%
\bibitem[Tully \& Fisher(1977)]{Tully:Fisher:77}
   Tully, R.B., \& Fisher, J.R. 1977,
   % A new method of determining distances to galaxies
   {\em A\&A} {\bf 54}, 661.
%
% \bibitem[Udalski et~al.(1999a)]{Udalski:etal:99a}
%    Udalski, A., et~al. 1999a,
%    % The Optical Gravitational Lensing Experiment. Cepheids in the
%    % Magellanic Clouds. III. Period-Luminosity-Color and
%    % Period-Luminosity Relations of Classical Cepheids,
%    AcA {\bf 49}, 201.
%
\bibitem[Udalski et~al.(1999a)]{Udalski:etal:99a}
   Udalski, A., et~al. 1999a,
   % The Optical Gravitational Lensing Experiment. Cepheids in the
   % Magellanic Clouds. IV. Catalog of Cepheids from the 
   % Large  Magellanic Cloud,
   {\em AcA} {\bf 49}, 223.
%
\bibitem[Udalski et~al.(1999b)]{Udalski:etal:99b}
   Udalski, A., et~al. 1999b,
   % The Optical Gravitational Lensing Experiment. Cepheids in the
   % Magellanic Clouds. V. Catalog of Cepheids from the 
   % Small Magellanic Cloud,
   {\em AcA} {\bf 49}, 437.
%
\bibitem[van den Bergh(1960)]{vandenBergh:60}
   van den Bergh, S. 1960,
   % The Extragalactic Distance Scale
   {\em J.~R. Ast. Soc. Canada} {\bf 54}, 49.
%
\bibitem[van den Bergh et~al.(1985)van den Bergh, Pritchet, \&
   Grillmair]{vandenBergh:etal:85} 
   van den Bergh, S., Pritchet, C., \& Grillmair, C. 1985,
   % Globular clusters and the distance to M87
   {\em AJ} {\bf 90}, 595.  
%
\bibitem[van Maanen(1923)]{vanMaanen:23}
   van Maanen, A. 1923,
   {\em ApJ} {\bf 57}, 264 (and references therein).
%
\bibitem[Wirtz(1918)]{Wirtz:18}
   Wirtz, C. 1918,
   {\em A.N.} {\bf 206}, 109.
%
\bibitem[Wirtz(1925)]{Wirtz:25}
   Wirtz, C. 1925,
   {\em Scientia} {\bf 38}, 303.
%
\bibitem[Yahil, Tammann, \& Sandage(1977)]{Yahil:etal:77}
   Yahil, A., Tammann, G.A., \& Sandage, A. 1977, 
   % The Local Group - The solar motion relative to its centroid
   {\em ApJ} {\bf 217}, 903.
%
\bibitem[Zwicky(1933)]{Zwicky:33}
   Zwicky, F. 1933,
   {\em Helv. Phys. Acta} {\bf 6}, 110.

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%
\bibitem[Baade(1944)]{Baade:44}
   Baade, W. 1944,
   {\em ApJ} {\bf 100}, 137.
%
\bibitem[Baade(1952)]{Baade:52}
   Baade, W. 1952,
   {\em I.A.U. Trans.} VIII (Cambridge: Cambridge Univ. Press), p. 397.
%
\bibitem[Baade(1963)]{Baade:63}
   Baade, W. 1963,
   {\em Evolution of Stars and Galaxies}, ed. C. Payne-Gaposchkin,
   (Cambridge, Mass.: Harvard Univ. Press), p.~28. 
%
\bibitem[Baade \& Swope(1954)]{Baade:Swope:54}
   Baade, W., \& Swope, H.H. 1954,
   {\em Yearbook Carnegie Inst.} {\bf 53}, 20.
%
\bibitem[Baade \& Swope(1963)]{Baade:Swope:63}
   Baade, W., \& Swope, H.H. 1963,
   % Variable star field 96' south preceeding the nucleous oftheAnd
   % galaxy. 
   {\em AJ} {\bf 68}, 435.
%
\bibitem[Behr(1951)]{Behr:51}
   Behr, A. 1951,
   % Zur Entfernungsskala der extragalaktischen Nebel
   {\em A.N.} {\bf 279}, 97.
%
\bibitem[Berdnikov et~al.(2000)Berdnikov, Dambis, \&
   Voziakova]{Berdnikov:etal:00} 
   Berdnikov, L.N., Dambis, A.K., \& Voziakova, O.V., 2000,
   % Galactic Cepheids. Catalogue of light-curve parameters and
   % distances 
   {\em A\&AS} {\bf 143}, 211.
%
\bibitem[Bottinelli et~al.(1986)]{Bottinelli:etal:86}
   Bottinelli, L., Gouguenheim, L., Paturel, G., \& Teerikorpi,
   P. 1986,
   % The Malmquist bias and the value of H0 from the Tully-Fisher
   % relation 
   {\em A\&A} {\bf 156}, 157.
%
\bibitem[Bottinelli et~al.(1991)]{Bottinelli:etal:91}
   Bottinelli, L., Gouguenheim, L., Paturel, G., \& Teerikorpi,
   P. 1991,
   % A systematic effect in the use of planetary nebulae as standard
   % candles 
   {\em A\&A} {\bf 252}, 550.
%
\bibitem[Corey \& Wilkinson(1976)]{Corey:Wilkinson:76}
   Corey, B.E., \& Wilkinson, D.T. 1976,
   {\em BAAS} {\bf 8}, 351.
%
\bibitem[da Costa et~al.(2000)]{daCosta:etal:00}
   da Costa, L.N., et~al. 2000,
   % Redshift-Distance Survey of Early-Type Galaxies: Dipole of the
   % Velocity Field 
   {\em ApJ} {\bf 537}, L81.
%
\bibitem[Dale et~al.(1999)]{Dale:etal:99}
   Dale, D.A., Giovanelli, R., Haynes, M.P., Campusano, L.E., \&
   Hardy, E. 1999,
   % Seeking the Local Convergence Depth. V. Tully-Fisher Peculiar
   % Velocities for 52 Abell Clusters 
   {\em AJ} {\bf 118}, 1489.
%
\bibitem[Davis \& Peebles(1983)]{Davis:Peebles:83}
   Davis, M., \& Peebles, P.J.E. 1983,
   % Evidence for local anisotropy of the Hubble flow
   {\em ARA\&A} {\bf 21}, 109.
%
\bibitem[de Sitter(1916)]{deSitter:16}
   de Sitter, W. 1916,
   % Einstein's theory of gravitation and its astronomical consequences
   {\em MNRAS} {\bf 76}, 699.
%
\bibitem[de Sitter(1917)]{deSitter:17}
   de Sitter, W. 1917,
   % Einstein's theory of gravitation and its astronomical
   % consequences. Third paper 
   {\em MNRAS} {\bf 78}, 3.
%
\bibitem[de Sitter(1930)]{deSitter:30}
   de Sitter, W. 1930,
   % On the magnitudes, diameters and distances of the extragalactic
   % nebulae and their apparent radial velocities (Errata: 5 V, 230) 
   {\em BAN} {\bf 5}, 157.
%
\bibitem[de Vaucouleurs(1970)]{deVaucouleurs:70}
   de Vaucouleurs, G. 1970,
   % The Brightest Star Clusters in Galaxies as Distance Indicators 
   {\em ApJ} {\bf 159}, 435.
%
\bibitem[de Vaucouleurs(1977)]{deVaucouleurs:77}
   de Vaucouleurs, G. 1977,
   % Distances de Groupes et Amas Proches et la Valeur Locale DU
   % Rapport de Hubble 
   in: {\em D{\'e}calage vers le rouge et expansion de l'univers},
   eds. C. Balkowski \&  B.E. Westerlund, IAU Coll. {\bf 37}, (Paris:
   Ed. CNRS), p.~301. 
%
\bibitem[de Vaucouleurs(1978)]{deVaucouleurs:78}
   de Vaucouleurs, G. 1978,
   % The extragalactic distance scale. IV - Distances of nearest
   % groups and field galaxies from secondary indicators 
   {\em ApJ} {\bf 224}, 710.
%
\bibitem[de Vaucouleurs \& Bollinger(1979)]{deVaucouleurs:Bollinger:79}
   de Vaucouleurs, G., \& Bollinger, G. 1979,
   % The extragalactic distance scale. VII - The velocity-distance
   % relations in different directions and the Hubble ratio within and
   % without the local supercluster 
   {\em ApJ} {\bf 233}, 433.
%
\bibitem[de Vaucouleurs \& Peters(1985)]{deVaucouleurs:Peters:85}
   de Vaucouleurs, G., \& Peters, W. 1985,
   % A preliminary mapping of the extragalactic velocity field near
   % the plane of the local supercluster 
   {\em ApJ} {\bf 297}, 27.
%
\bibitem[Djorgovski \& Davis(1987)]{Djorgovski:Davis:87}
   Djorgovski, S., \& Davis, M. 1987,
   % Fundamental properties of elliptical galaxies
   {\em ApJ} {\bf 313}, 59.
%
\bibitem[Dressler et~al.(1987)]{Dressler:etal:87}
   Dressler, A., Faber, S.M., Burstein, D., Davies, R.L., Lynden-Bell,
   D., Terlevich, R.J., \& Wegner, G. 1987,
   % Spectroscopy and photometry of elliptical galaxies - A
   % large-scale streaming motion in the local universe 
   {\em ApJ} {\bf 313}, L37.
%
\bibitem[Durrer(2002)]{Durrer:02}
   Durrer, R. 2002,
   in: {\em Matter in the Universe}, eds. Ph. Jetzer, K. Pretzl, \&
   R. von Steiger, (Dordrecht: Kluwer), p.~3.
%
\bibitem[Ekholm et~al.(1999)]{Ekholm:etal:99}
   Ekholm, T., Teerikorpi, P., Theureau, G., Hanski, M., Paturel, G.,
   Bottinelli, L., \& Gouguenheim, L. 1999,
   % Kinematics of the local Universe. X. H_0 from the inverse B-band
   % Tully-Fisher relation using diameter and magnitude limited samples 
   {\em A\&A} {\bf 347}, 99.
%
\bibitem[Ekholm et~al.(2001)]{Ekholm:etal:01}
   Ekholm, T., Baryshev, Y., Teerikorpi, P., Hanski, M., \&  Paturel,
   G. 2001,
   % On the quiescence of the Hubble flow in the vicinity of the Local
   % Group. A study using galaxies with distances from the Cepheid
   % PL-relation 
   A\&A {\bf 368}, 17.
%
\bibitem[Faber \& Jackson(1976)]{Faber:Jackson:76}
   Faber, S.M., \& Jackson, R.E. 1976,
   % Velocity dispersions and mass-to-light ratios for elliptical
   % galaxies 
   {\em ApJ} {\bf 204}, 668.
%
\bibitem[Feast(1999)]{Feast:99}
   Feast, M.W. 1999,
   % Cepheids as Distance Indicators
   {\em PASP} {\bf 111}, 775.
%
\bibitem[Federspiel(1999)]{Federspiel:99}
   Federspiel, M. 1999,
   Ph.D. Thesis, Univ. Basel.
%
\bibitem[Federspiel et~al.(1994)Federspiel, Sandage, \&
Tammann]{Federspiel:etal:94} 
   Federspiel, M., Sandage, A., \& Tammann, G.A. 1994,
   % Bias properties of extragalactic distance indicators. 3: Analysis
   % of Tully-Fisher distances for the Mathewson-Ford-Buchhorn sample
   % of 1355 galaxies 
   {\em ApJ} {\bf 430}, 29.
%
\bibitem[Fernie(1970)]{Fernie:70}
   Fernie, J.D. 1995,
   %  The Historical Quest for the Nature of the Spiral Nebulae
   {\em PASP} {\bf 82}, 1189.
%
\bibitem[Fernie et~al.(1995)]{Fernie:etal:95}
   Fernie, J.D., Beattie, B., Evans, N.R., \& Seager, S. 1995,
   %  A Database of Galactic Classical Cepheids
   {\em IBVS} {\bf 4148}. 
%
\bibitem[Ford \& Jenner(1978)]{Ford:Jenner:78}
   Ford, H.C., \& Jenner, D.C. 1978,
   % Planetary Nebulae in the Nuclear Bulge of M81: A New Distance
   % Determination 
   {\em BAAS} {\bf 10}, 665.
%
\bibitem[Freedman et~al.(2001)]{Freedman:etal:01}
   Freedman, W.L., et~al. 2001,
   % Final Results from the Hubble Space Telescope Key Project to
   % Measure the Hubble Constant 
   {\em ApJ} {\bf 553}, 47.
%
\bibitem[Gieren et~al.(1998)Gieren, Fouqu{\'e}, \& Gomez]{Gieren:etal:98}
   Gieren, W.P., Fouqu{\'e}, P., \& Gomez, M. 1998,
   %  Cepheid Period-Radius and Period-Luminosity Relations and the
   %  Distance to the Large Magellanic Cloud 
   {\em ApJ} {\bf 496}, 17.
%
\bibitem[Giovanelli et~al.(1997)]{Giovanelli:etal:97}
   Giovanelli, R., et~al. 1997,
   %  The I band Tully-Fisher relation for cluster galaxies: data
   % presentation.  
   {\em AJ} {\bf 113}, 22.
%
\bibitem[Goodwin et~al.(1997)]{Goodwin:etal:97}
   Goodwin, S.P., Gribbin, J., \& Hendry, M.A. 1997,
   % A new Determination of the Hubble Parameter using Galaxy Linear
   % Diameters 
   {\em AJ} {\bf 114}, 2212.
%
\bibitem[Hamuy(2001)]{Hamuy:01}
   Hamuy, M.A. 2001,
   Ph.D. Thesis, Univ. of Arizona.
%
\bibitem[Gouguenheim(1969)]{Gouguenheim:69}
   Gouguenheim, L. 1969,
   % Neutral hydrogen content of small galaxies
   {\em A\&A} {\bf 3}, 281 (eq. 11c).
%
\bibitem[Hanes(1982)]{Hanes:82}
   Hanes, D.A. 1982,
   % A re-examination of the Sandage-Tammann extragalactic distance
   % scale 
   {\em MNRAS} {\bf 201}, 145.
%
\bibitem[Hendry(2002)]{Hendry:02}
   Hendry, M. 2002,
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., in press.
%
\bibitem[Hertzsprung(1914)]{Hertzsprung:14}
   Hertzsprung, E. 1913,
   % Ueber die raeumliche Verteilung der Veraenderlichen vom d
   % Cephei-Typus 
   {\em A.N.} {\bf 196}, 201.
%
\bibitem[Holmberg(1958)]{Holmberg:58}
   Holmberg, E. 1958,
   % A photographic photometry of extragalactic nebulae
   {\em Medd. Lunds Astr. Obs.} {\bf 2}, No.\,136.
%
\bibitem[Hubble(1925)]{Hubble:25}
   Hubble, E. 1925,
   % NGC 6822, a remote stellar system
   {\em ApJ} {\bf 62}, 409.
%
\bibitem[Hubble(1926)]{Hubble:26}
   Hubble, E. 1926,
   % A spiral nebula as a stellar system: Messier 33
   {\em ApJ} {\bf 63}, 236.
%
\bibitem[Hubble(1929a)]{Hubble:29a}
   Hubble, E. 1929a,
   % A spiral nebula as a stellar system, Messier 31
   {\em ApJ} {\bf 69}, 103.
%
\bibitem[Hubble(1929b)]{Hubble:29b}
   Hubble, E. 1929b,
   {\em Proc. Nat. Acad. Sci.} {\bf 15}, 168.
%
\bibitem[Hubble(1936a)]{Hubble:36a}
   Hubble, E. 1936a,
   {\em The Realm of Nebulae} (New Haven: Yale Univ. Press).
%
\bibitem[Hubble(1936b)]{Hubble:36b}
   Hubble, E. 1936b,
   % Effects of Red Shifts on the Distribution of Nebulae
   {\em ApJ} {\bf 84}, 517.
%
\bibitem[Hubble(1953)]{Hubble:53}
   Hubble, E. 1953,
   % The law of red shifts (George Darwin Lecture)
   {\em MNRAS} {\bf 113}, 658.
%
\bibitem[Hubble \& Humason(1931)]{Hubble:Humason:31}
   Hubble, E., \& Humason, M.L. 1931,
   % The Velocity-Distance Relation among Extra-Galactic Nebulae
   {\em ApJ} {\bf 74}, 43.
%
\bibitem[Hubble \& Humason(1934)]{Hubble:Humason:34}
   Hubble, E., \& Humason, M.L. 1934,
   % The Velocity-distance Relation for Isolated Extragalactic Nebulae 
   {\em Proc. Nat. Acad. Sci. USA} {\bf 20}, 264.
%
\bibitem[Humason(1936)]{Humason:36}
   Humason, M.L. 1936,
   % The Apparent Radial Velocities of 100 Extra-Galactic Nebulae
   {\em ApJ} {\bf 83}, 10.
%
\bibitem[HMS(1956)Humason, Mayall, \& Sandage]{Humason:etal:56}
   Humason, M.L., Mayall, N.U., \& Sandage, A.R. 1956,
   % Redshifts and magnitudes of extragalactic nebulae
   {\em AJ} {\bf 61}, 97 (HMS).
%
\bibitem[Humphreys \& Strom(1983)]{Humphreys:Strom:83}
   Humphreys, R.M., \& Strom, S.E. 1983,
   % M supergiants and the distance to M101
   {\em ApJ} {\bf 264}, 458.
%
\bibitem[Karachentsev et~al.(2002)]{Karachentsev:etal:02}
   Karachentsev, et~al. 2002,
   % The very local Hubble flow
   {\em A\&A} {\bf 389}, 812.
%
\bibitem[Kelson et~al.(1996)]{Kelson:etal:96}
   Kelson, et~al. 1996,
   % The Extragalactic Distance Scale Key Project. III. The Discovery
   % of Cepheids and a New Distance to M101 Using the Hubble Space
   % Telescope 
   {\em ApJ} {\bf 463}, 26.
%
\bibitem[Kelson et~al.(2000)]{Kelson:etal:00}
   Kelson, et~al. 2000,
   % The Hubble Space Telescope Key Project on the Extragalactic
   % Distance Scale. XXVII. A Derivation of the Hubble Constant Using
   % the Fundamental Plane and Dn-s Relations in Leo I, Virgo, and
   % Fornax 
   {\em ApJ} {\bf 529}, 768.
%
\bibitem[Kowal(1968)]{Kowal:68}
   Kowal, C.T. 1968,
   % Absolute magnitudes of supernovae 
   {\em AJ} {\bf 73}, 1021.
%
\bibitem[Kraan-Korteweg(1986)]{Kraan-Korteweg:86}
   Kraan-Korteweg, R.C. 1986,
   % A catalog of 2810 nearby galaxies - The effect of the
   % Virgocentric flow model on their observed velocities 
   {\em A\&AS} {\bf 66}, 255.
%
\bibitem[Kraan-Korteweg, Cameron, \& Tammann(1988)]{Kraan-Korteweg:etal:88}
   Kraan-Korteweg, R.C., Cameron, L.M., \& Tammann, G.A. 1988,
   % 21 centimeter line width distances of cluster galaxies and the
   % value of Ho 
   {\em ApJ} {\bf 331}, 620.
%
\bibitem[Lasenby(2002)]{Lasenby:02}
   Lasenby, A. 2002,
   Talk presented at a Coll., Basel 26.06.2002.
%
\bibitem[Lema{\^i}tre(1927)]{Lemaitre:27}
   Lema{\^i}tre, G. 1927,
   {\em Ann. Soc. Sci. Bruxelles} {\bf 47}, 49. (English translation
   in {\em MNRAS} {\bf 91}, 483 [1931]).
%
\bibitem[Lundmark(1920)]{Lundmark:20}
   Lundmark, K. 1920,
   {\em The relation of the globular clusters and spiral nebulae to
   the stellar system},
   (Stockholm: Handlingar).
%
\bibitem[Lundmark(1925)]{Lundmark:25}
   Lundmark, K. 1925,
   % Nebulae, The motions and the distances of spiral
   {\em MNRAS} {\bf 85}, 865.
%
\bibitem[Madore(1976)]{Madore:76}
   Madore, B.F. 1976,
   % The distance to NGC 2403
   {\em MNRAS} {\bf 177}, 157.
%
\bibitem[Malmquist(1920)]{Malmquist:20}
   Malmquist, G. 1920,
   {\em Medd. Lunds Astr. Obs.} {\bf 2}, No.\,22.
%
\bibitem[M{\'e}ndez et~al.(1993)]{Mendez:etal:93}
   M{\'e}ndez, R.H., Kudritzki, R.P.,  Ciardullo, R., \&  Jacoby, G.H.  1993,
   % The bright end of the planetary nebula luminosity function 
   {\em A\&A} {\bf 275}, 534.
%
\bibitem[Minkowski(1962)]{Minkowski:62}
   Minkowski 1962,
   % Internal Dispersion of Velocities in Other Galaxies
   in: {\em Problems of Extra-Galactic Research}, ed. G.C. McVittie,
   IAU Symp. {\bf 15}, (New York: Macmillan), p.~112.
   % oder: Identification with Optical Objects, p.~201
%
\bibitem[Mineur(1945)]{Mineur:45}
   Mineur, H. 1945,
   {\em C.\,R. Acad. Sci. Paris} {\bf 220}, 445.
%
\bibitem[Nadyozhin(2002)]{Nadyozhin:02}
   Nadyozhin, D.K., 2002,
   in: {\em From Twilight to Highlight, the Physics of Supernovae},
   ESO/MPA/MPE Workshop, in press.
%
\bibitem[Netterfield et~al.(2002)]{Netterfield:etal:02}
   Netterfield, C.B., et~al. 2002,
   % A Measurement by BOOMERANG of Multiple Peaks in the Angular Power
   % Spectrum of the Cosmic Microwave Background 
   {\em ApJ} {\bf 571}, 604.
%
\bibitem[{\"O}pik(1921)]{Oepik:21}
   {\"O}pik, E. 1921,
   {\em Weltkunde} (Russian) {\bf 10}, 12.
%
\bibitem[{\"O}pik(1922)]{Oepik:22}
   {\"O}pik, E. 1922,
   % An estimate of the distance of the Andromeda Nebula
   {\em ApJ} {\bf 55}, 406.
%
\bibitem[Parodi et~al.(2000)]{Parodi:etal:00}
   Parodi, B.R., Saha, A., Sandage, A., \& Tammann, G.A. 2000,
   % Supernova Type Ia Luminosities, Their Dependence on Second
   % Parameters, and the Value of Ho
   {\em ApJ} {\bf 540}, 634.
%
\bibitem[Paturel et~al.(1998)]{Paturel:etal:98}
   Paturel, G., et~al. 1998,
   % Hubble constant from sosie galaxies and HIPPARCOS geometrical
   % calibration 
   {\em A\&A} {\bf 339}, 671.
%
\bibitem[Peebles(1976)]{Peebles:76}
   Peebles, P.J.E. 1976,
   % The Peculiar Velocity Field in the Local Supercluster
   {\em ApJ} {\bf 205}, 318.
%
\bibitem[Phillips(1993)]{Phillips:93}
   Phillips, M.M. 1993,
   % The absolute magnitudes of Type IA supernovae
   {\em ApJ} {\bf 413}, L105.
%
\bibitem[Pryke(2002)]{Pryke:02}
   Pryke, C. 2002,
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., in press.
%
\bibitem[Ritchey(1917)]{Ritchey:17}
   Ritchey, G.W. 1917,
   % Novae in Spiral Nebulae
   {\em PASP} {\bf 29}, 207.
%
\bibitem[Robertson(1928)]{Robertson:28}
   Robertson, H.P. 1928,
   {\em Phil. Mag.} {\bf 5}, 835.
%
\bibitem[Saha et~al.(2001)]{Saha:etal:01}
   Saha, A., Sandage, A., Tammann, G.A., Dolphin, A.E., Christensen,
   J., Panagia, N., \& Macchetto, E.D. 2001,
   % Cepheid Calibration of the Peak Brightness of Type Ia
   % Supernovae. XI. SN 1998aq in NGC 3982 
   {\em ApJ} {\bf 562}, 314.
%
\bibitem[Saha(2002)]{Saha:02}
   Saha, P. 2002,
   Talk presented at a Coll., Basel 26.06.2002.
%
\bibitem[Sakai et~al.(2000)]{Sakai:etal:00}
   Sakai, et~al. 2000,
   % The Hubble Space Telescope Key Project on the Extragalactic
   % Distance Scale. XXIV. The Calibration of Tully-Fisher Relations and
   % the Value of the Hubble Constant 
   {\em ApJ} {\bf 529}, 698.
%
\bibitem[Sandage(1953)]{Sandage:53}
   Sandage, A. 1953,
   % The color-magnitude diagram for the globular cluster M3
   {\em AJ} {\bf 58}, 61.
%
\bibitem[Sandage(1954)]{Sandage:54}
   Sandage, A. 1954,
   % The first four years of extragalactic research with the Hale
   % 200-inch telescope 
   {\em AJ} {\bf 59}, 180.
%
\bibitem[Sandage(1958)]{Sandage:58}
   Sandage, A. 1958,
   % Current Problems in the Extragalactic Distance Scale
   {\em ApJ} {\bf 127}, 513.
%
\bibitem[Sandage(1962)]{Sandage:62}
   Sandage, A. 1962,
   % The Distance Scale
   in: {\em Problems of Extra-Galactic Research}, ed. G.C. McVittie,
   IAU Symp. {\bf 15}, (New York: Macmillan), p.~359.
%
\bibitem[Sandage(1972)]{Sandage:72}
   Sandage, A. 1972,
   % The redshift-distance relation. II. The Hubble diagram and its
   % scatter for first-ranked cluster galaxies: a formal value for qo 
   {\em ApJ} {\bf 178}, 1.
%
\bibitem[Sandage(1986)]{Sandage:86}
   Sandage, A. 1986,
   % The redshift-distance relation. IX - Perturbation of the very
   % nearby velocity field by the mass of the Local Group 
   {\em ApJ} {\bf 307}, 1.
%
\bibitem[Sandage(1995)]{Sandage:95}
   Sandage, A. 1995,
   in: {\em The Deep Universe}, 
   Saas-Fee Advanced Course {\bf 23}, 
   eds. B. Binggeli \& R. Buser, 
   (Berlin: Springer), p.~1.
%
\bibitem[Sandage(1996)]{Sandage:96}
   Sandage, A. 1996,
   % Bias Properties of Extragalactic Distance Indicators. V.Ho From
   % Luminosity Functions of Different Spiral Types and Luminosity
   % Classes Corrected for Bias 
   % 
   % Bias Properties of Extragalactic Distance
   % Indicators. VI. Luminosity Functions of M31 and M101 Look-alikes
   % Listed in the RSA2: Ho Therefrom 
   {\em AJ} {\bf 111}, 1 and 18.
%
\bibitem[Sandage(1998)]{Sandage:98}
   Sandage, A. 1998,
   % SN 1932 GAT: A Supernova of Unique Class
   in: {\em Supernovae and Cosmology}, 
   eds. L. Labhardt, B. Binggeli, \& R. Buser, 
   (Basel: Astron. Inst.), p.~201.
%
\bibitem[Sandage(1999a)]{Sandage:99a}
   Sandage, A. 1999a,
   % The First 50 Years at Palomar: 1949-1999 The Early Years of
   % Stellar Evolution, Cosmology, and High-Energy Astrophysics 
   {\em ARA\&A} {\bf 37}, 445.
%
\bibitem[Sandage(1999b)]{Sandage:99b}
   Sandage, A. 1999b,
   % Bias Properties of Extragalactic Distance Indicators. VIII. H0
   % from Distance-limited Luminosity Class and Morphological
   % Type-Specific Luminosity Functions for SB, SBC, and SC Galaxies
   % Calibrated Using Cepheids 
   {\em ApJ} {\bf 527}, 479.
%
\bibitem[Sandage(2002)]{Sandage:02}
   Sandage, A. 2002,
   % Bias Properties of Extragalactic Distance Indicators. X. The
   % Teerikorpi Cluster Population Incompleteness Bias for a Modified
   % Lema�tre-Robertson-Hubble-Humason Distance Method That Uses
   % Luminosity Functions 
   {\em AJ} {\bf 123}, 1179.
%
\bibitem[Sandage \& Hardy(1973)]{Sandage:Hardy:73}
   Sandage, A., \& Hardy, E. 1973,
   % The Redshift-Distance Relation. VIL Absolute Magnitudes of the
   % First Three Ranked Cluster Galaxies as Functions of Cluster
   % Richness and Bautz-Morgan Cluster Type: the Effect of qo 
   {\em ApJ} {\bf 183}, 743.
%
\bibitem[Sandage et~al.(1976)Sandage, Kristian, \& Westphal]{Sandage:etal:76}
   Sandage, A., Kristian, J., \& Westphal, J.A. 1976,
   % The extension of the Hubble diagram. I. New redshifts and BVR
   % photometry of remote cluster galaxies, and an improved richness
   % correction 
   {\em ApJ} {\bf 205}, 688.
%
\bibitem[Sandage \& Tammann(1968)]{Sandage:Tammann:68}
   Sandage, A., \& Tammann, G.A. 1968,
   % A Composite Period-Luminosity Relation for Cepheids at Mean and
   % Maximum Light 
   {\em ApJ} {\bf 151}, 531.
%
\bibitem[Sandage \& Tammann(1974a)]{Sandage:Tammann:74a}
   Sandage, A., \& Tammann, G.A. 1974a,
   % Steps toward the Hubble constant. III - The distance and stellar
   % content of the M101 group of galaxies 
   {\em ApJ} {\bf 194}, 223.
%
\bibitem[Sandage \& Tammann(1974b)]{Sandage:Tammann:74b}
   Sandage, A., \& Tammann, G.A. 1974b,
   % Steps toward the Hubble constant. IV - Distances to 39 galaxies
   % in the general field leading to a calibration of the galaxy
   % luminosity classes and a first hint of the value of Ho 
   {\em ApJ} {\bf 194}, 559.
%
\bibitem[Sandage \& Tammann(1975)]{Sandage:Tammann:75}
   Sandage, A., \& Tammann, G.A. 1975,
   % Steps toward the Hubble constant. VI - The Hubble constant
   % determined from redshifts and magnitudes of remote SC I galaxies:
   % The value of qo 
   {\em ApJ} {\bf 197}, 265.
%
\bibitem[Sandage \& Tammann(1976)]{Sandage:Tammann:76}
   Sandage, A., \& Tammann, G.A. 1976,
   % Steps toward the Hubble constant. VII - Distances to NGC 2403,
   % M101, and the Virgo cluster using 21 centimeter line widths
   % compared with optical methods: The global value of Ho 
   {\em ApJ} {\bf 210}, 7. 
%
\bibitem[Sandage \& Tammann(1982)]{Sandage:Tammann:82}
   Sandage, A., \& Tammann, G.A. 1982,
   % Steps toward the Hubble constant. VIII - The global value
   {\em ApJ} {\bf 256}, 339.
%
\bibitem[Sandage et~al.(1995)Sandage, Tammann, \&
Federspiel]{Sandage:etal:95} 
   Sandage, A., Tammann, G.A., \& Federspiel, M. 1995,
   % Bias Properties of Extragalactic Distance
   % Indicators. IV. Demonstration of the Population Incompleteness
   % Bias Inherent in the Tully-Fisher Method Applied to Clusters 
   {\em ApJ} {\bf 452}, 1.
%
\bibitem[Schlegel et~al.(1998)Schlegel, Finkbeiner, \& Davis]{Schlegel:etal:98}
   Schlegel, D., Finkbeiner, D., \& Davis, M. 1998,
   % Maps of Dust Infrared Emission for Use in Estimation of Reddening
   % and Cosmic Microwave Background Radiation Foregrounds 
   {\em ApJ} {\bf 500}, 525.
%
\bibitem[Shapley(1915)]{Shapley:15}
   Shapley, H. 1915,
   % Studies based on the colors and magnitudes in stellar
   % clusters. II. Thirteeen hundred stars in the Hercules Cluster
   % (Messier 13) 
   {\em Mt. Wilson Contrib.} {\bf 116}, 82.
%
\bibitem[Shapley(1918)]{Shapley:18}
   Shapley, H. 1918,
   % Studies based on the colors and magnitudes in stellar
   % clusters. VII. The distances, distribution in space, and dimensions
   % of 69 globular clusters 
   {\em ApJ} {\bf 48}, 154.
%
\bibitem[S{\'e}rsic(1960)]{Sersic:60}
   S{\'e}rsic, J.L. 1960,
   {\em Zs. f. Ap.} {\bf 50}, 168.
%
\bibitem[Slipher(1914)]{Slipher:14}
   Slipher, V.M. 1914,
   {\em Bulletin Lowell Obs.} {\bf 62}, 66.
%
\bibitem[Smoot, Gorenstein, \& Muller(1977)]{Smoot:etal:77}
   Smoot, G.F., Gorenstein, M.V., \& Muller, R.A. 1977, 
   % Detection of anisotropy in the cosmic blackbody radiation 
   {\em Phys. Rev. Lett.} {\bf 39}, 898.

%
\bibitem[Stebbins et~al.(1950)Stebbins, Whitford \& Johnson]{Stebbins:etal:50}
   Stebbins, J., Whitford, A.E., \& Johnson, H.L. 1950,
   % Photoelectric Magnitudes and Colors of Stars in Selected Areas
   % 57, 61, and 68 
   {\em ApJ} {\bf 112}, 469.
%
\bibitem[Stromberg(1925)]{Stromberg:25}
   Stromberg, G. 1925,
   % Analysis of radial velocities of globular clusters and
   % non-galactic nebulae
   {\em ApJ} {\bf 61}, 353.
%
\bibitem[Tammann(1993)]{Tammann:93}
   Tammann, G.A. 1993,
   % Why are Planetary Nebulae Poor Distance Indicators?
   in: {\em Planetary Nebulae}, eds. R. Weinberger \&  A. Acker,
   IAU Symp. {\bf 155}, p.~515.
%
\bibitem[Tammann \& Kraan-Korteweg(1978)]{Tammann:Kraan-Korteweg:78}
   Tammann, G.A., \& Kraan-Korteweg, R. 1978,
   % The galactic neighbourhood
   in: {\em Large Scale Structure of the Universe},
   eds. M.S. Longair \& J. Einasto, 
   IAU Symp. {\bf 79}, p.~71.
%
\bibitem[Tammann, Reindl, \& Thim(2001a)]{Tammann:etal:01a}
   Tammann, G.A., Reindl, B., \& Thim, F. 2001a,
   % Supernovae and the Large-Scale Value of Ho
   in: {\em Cosmology and Particle Physics}, eds. R. Durrer,
   J. Garcia-Bellido, \& M. Shaposhnikov, (Melville: Am. Inst. Phys.),
   p.~226. 
%
\bibitem[Tammann et~al.(2001b)]{Tammann:etal:01b}
   Tammann, G.A., Reindl, B., Thim, F., Saha, A., \& Sandage,
   A. 2001b,
   % Cepheids, Supernovae, Ho, and the Age of the Universe
   in: {\em A New Era in Cosmology}, eds. T. Shanks \& N. Metcalfe,
   ASP Conf. Ser., astro-ph/0112489.
%
\bibitem[Tammann \& Sandage(1968)]{Tammann:Sandage:68}
   Tammann, G.A., \& Sandage, A. 1968,
   % The Stellar Content and Distance of the Galaxy NGC 2403 IN the
   % M81 Group 
   {\em ApJ} {\bf 151}, 825.
%
\bibitem[Tammann \& Sandage(1985)]{Tammann:Sandage:85}
   Tammann, G.A., \& Sandage, A. 1985,
   % The infall velocity toward Virgo, the Hubble constant, and a
   % search for motion toward the microwave background 
   {\em ApJ} {\bf 294}, 81.
%
\bibitem[Tammann \& Sandage(1995)]{Tammann:Sandage:95}
   Tammann, G.A., \& Sandage, A. 1995,
   % The Hubble Diagram for Supernovae of Type Ia. II. The Effect on
   % the Hubble Constant of a Correlation between Absolute Magnitude and
   % Light Decay Rate 
   {\em ApJ} {\bf 452}, 16.
%
\bibitem[Tammann \& Sandage(1999)]{Tammann:Sandage:99}
   Tammann, G.A., \& Sandage, A. 1999,
   % The Luminosity Function of Globular Clusters as an Extragalactic
   % Distance Indicator 
   in: {\em Harmonizing Cosmic Distance Scales in a Post-Hipparcos
   Era}, eds. D. Egret \& A. Heck, ASP Conf. Ser. {\bf 167}, p.~204.
%
\bibitem[Teerikorpi(1984)]{Teerikorpi:84}
   Teerikorpi, P. 1984,
   % Malmquist bias in a relation of the form M = AP + B
   {\em A\&A} {\bf 141}, 407.
%
\bibitem[Teerikorpi(1987)]{Teerikorpi:87}
   Teerikorpi, P. 1987,
   % Cluster population incompleteness bias and distances from the
   % Tully-Fisher relation - Theory and numerical examples 
   {\em A\&A} {\bf 173}, 39.
%
\bibitem[Teerikorpi(1997)]{Teerikorpi:97}
   Teerikorpi, P. 1997,
   % Observational Selection Bias Affecting the Determination of the
   % Extragalactic Distance Scale 
   {\em ARA\&A} {\bf 35}, 101.
%
\bibitem[Teerikorpi et~al.(1999)]{Teerikorpi:etal:99}
   Teerikorpi, P., Ekholm, T., Hanski, M.O., \& Theureau, G. 1999,
   % Theoretical aspects of the inverse Tully-Fisher relation as a
   % distance indicator: incompleteness in log {V_Max}, the relevant
   % slope, and the calibrator sample bias 
   {\em A\&A} {\bf 343}, 713.
%
\bibitem[Theureau et~al.(1997)]{Theureau:etal:97}
   Theureau, G., Hanski, M., Ekholm, T., Bottinelli, L., Gouguenheim,
   L., Paturel, G., \& Teerikorpi, P. 1997,
   % Kinematics of the Local Universe. V. The value of H_0_ from the
   % Tully-Fisher B and logD_25_ relations for field galaxies. 
   {\em A\&A} {\bf 322}, 730.
%
\bibitem[Theureau(2000)]{Theureau:00}
   Theureau, G. 2000,
   in: XIXth Texas Symposium, eds. E. Augbourg et~al., Mini-Symp. 13/12.
%
\bibitem[Tonry \& Schneider(1988)]{Tonry:Schneider:88}
   Tonry, J. \& Schneider, D.P. 1988,
   % A new technique for measuring extragalactic distances
   {\em AJ} {\bf 96}, 807.
%
\bibitem[Tripp(1998)]{Tripp:98}
   Tripp, R. 1998,
   % A two-parameter luminosity correction for Type IA supernovae
   {\em A\&A} {\bf 331}, 815.
%
\bibitem[Tully \& Fisher(1977)]{Tully:Fisher:77}
   Tully, R.B., \& Fisher, J.R. 1977,
   % A new method of determining distances to galaxies
   {\em A\&A} {\bf 54}, 661.
%
% \bibitem[Udalski et~al.(1999a)]{Udalski:etal:99a}
%    Udalski, A., et~al. 1999a,
%    % The Optical Gravitational Lensing Experiment. Cepheids in the
%    % Magellanic Clouds. III. Period-Luminosity-Color and
%    % Period-Luminosity Relations of Classical Cepheids,
%    AcA {\bf 49}, 201.
%
\bibitem[Udalski et~al.(1999a)]{Udalski:etal:99a}
   Udalski, A., et~al. 1999a,
   % The Optical Gravitational Lensing Experiment. Cepheids in the
   % Magellanic Clouds. IV. Catalog of Cepheids from the 
   % Large  Magellanic Cloud,
   {\em AcA} {\bf 49}, 223.
%
\bibitem[Udalski et~al.(1999b)]{Udalski:etal:99b}
   Udalski, A., et~al. 1999b,
   % The Optical Gravitational Lensing Experiment. Cepheids in the
   % Magellanic Clouds. V. Catalog of Cepheids from the 
   % Small Magellanic Cloud,
   {\em AcA} {\bf 49}, 437.
%
\bibitem[van den Bergh(1960)]{vandenBergh:60}
   van den Bergh, S. 1960,
   % The Extragalactic Distance Scale
   {\em J.~R. Ast. Soc. Canada} {\bf 54}, 49.
%
\bibitem[van den Bergh et~al.(1985)van den Bergh, Pritchet, \&
   Grillmair]{vandenBergh:etal:85} 
   van den Bergh, S., Pritchet, C., \& Grillmair, C. 1985,
   % Globular clusters and the distance to M87
   {\em AJ} {\bf 90}, 595.  
%
\bibitem[van Maanen(1923)]{vanMaanen:23}
   van Maanen, A. 1923,
   {\em ApJ} {\bf 57}, 264 (and references therein).
%
\bibitem[Wirtz(1918)]{Wirtz:18}
   Wirtz, C. 1918,
   {\em A.N.} {\bf 206}, 109.
%
\bibitem[Wirtz(1925)]{Wirtz:25}
   Wirtz, C. 1925,
   {\em Scientia} {\bf 38}, 303.
%
\bibitem[Yahil, Tammann, \& Sandage(1977)]{Yahil:etal:77}
   Yahil, A., Tammann, G.A., \& Sandage, A. 1977, 
   % The Local Group - The solar motion relative to its centroid
   {\em ApJ} {\bf 217}, 903.
%
\bibitem[Zwicky(1933)]{Zwicky:33}
   Zwicky, F. 1933,
   {\em Helv. Phys. Acta} {\bf 6}, 110.

%
\end{thebibliography}