Cumulenic cyclo[18]carbon
<a href="//commons.wikimedia.org/wiki/User:Micha%C5%82_Sobkowski" title="User:Michał Sobkowski">Michał Sobkowski</a>
Based on <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.aay1914">10.1126/science.aay1914 </a>