><code class="code">sunspots</code></dt>
<dd><p>Number of observed sunspots.
</p></dd>
</dl>

<h4 class="subsubheading" id="Source-63"><span>Source<a class="copiable-link" href="#Source-63"> &para;</a></span></h4>

<p>Andrews, D. F. and Herzberg, A. M. (1985) <cite class="cite">Data: A Collection
of Problems from Many Fields for the Student and Research Worker</cite>.
New York: Springer-Verlag.
</p>
<h4 class="subsubheading" id="Examples-62"><span>Examples<a class="copiable-link" href="#Examples-62"> &para;