cpython/Doc/tools/templates/indexsidebar.html

<h3>Download</h3>
<p><a href="{{ pathto('download') }}">Download these documents</a></p>
<h3>Docs for other versions</h3>
<ul>
  <li><a href="https://docs.python.org/2.7/">Python 2.7 (stable)</a></li>
  <li><a href="https://docs.python.org/3.4/">Python 3.4 (stable)</a></li>
  <li><a href="https://www.python.org/doc/versions/">Old versions</a></li>
</ul>

<h3>Other resources</h3>
<ul>
  {# XXX: many of these should probably be merged in the main docs #}
  <li><a href="https://www.python.org/dev/peps/">PEP Index</a></li>
  <li><a href="https://wiki.python.org/moin/BeginnersGuide">Beginner's Guide</a></li>
  <li><a href="https://wiki.python.org/moin/PythonBooks">Book List</a></li>
  <li><a href="https://www.python.org/doc/av/">Audio/Visual Talks</a></li>
</ul>