Struktur von Butan (Skelettformel)
<a href="//commons.wikimedia.org/w/index.php?title=User:Schemiker&amp;action=edit&amp;redlink=1" class="new" title="User:Schemiker (page does not exist)">Schemiker</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Schemiker" title="User talk:Schemiker"><span class="signature-talk">talk</span></a>)
2013-02-21
<span class="int-own-work" lang="en">Own work</span>