Numbering of carbon atoms in anthracene, according to <a rel="nofollow" class="external text" href="https://www.acdlabs.com/iupac/nomenclature/79/r79_72.htm">IUPAC recommendations 1979, rule A-22.5</a>.
<a href="//commons.wikimedia.org/wiki/User:Hbf878" title="User:Hbf878">Hbf878</a>
2019-01-14
<span class="int-own-work" lang="en">Own work</span>