Schéma <a href="https://en.wikipedia.org/wiki/cs:Kvartace" class="extiw" title="w:cs:Kvartace">kvartace</a>.
<a href="//commons.wikimedia.org/wiki/User:Juan_de_Vojn%C3%ADkov" class="mw-redirect" title="User:Juan de Vojníkov">Juan de Vojníkov</a>
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<span class="int-own-work" lang="en">Own work</span>