== Eksterne henvisninger ==
* [http://www.sengpielaudio.com/calculator-RT60Coeff.htm Absorption Coefficients α of Building Materials and Finishes]
* [http://www.engineeringtoolbox.com/accoustic-sound-absorption-d_68.html Sound Absorption Coefficients for Some Common Materials]
* [[Computation of radiowave attenuation in the atmosphere|Computations for Radio Wave Propagation]]
* [http://www.nist.gov/pml/data/xraycoef/index.cfm Tables of X-Ray Mass Attenuation Coefficients and Mass Energy-Absorption Coefficients from 1 keV to 20 MeV for Elements Z = 1 to 92 and 48 Additional Substances of Dosimetric Interest]
Filosofi Videnskab Naturvidenskab