Vondalhyde; maleic hydrazide; 1,2-Dihydro-3,6-pyridazinedione; Antergon; Antyrost
<a href="//commons.wikimedia.org/wiki/User:Yikrazuul" title="User:Yikrazuul">Yikrazuul</a>
<span class="int-own-work" lang="en">Own work</span>