Foto: "<a href="https://www.ccnull.de/foto/mann-haelt-gluehbirne-in-seiner-hand/1022498" target="_blank">Mann hält Glühbirne in seiner Hand</a>" von <a href="https://www.ccnull.de/fotograf/marco-verch" target="_blank">Marco Verch</a> via <a href="https://www.ccnull.de" target="_blank">ccnull.de</a> - <a href="https://www.flickr.com/photos/149561324@N03/27093331789/" target="_blank">Bildquelle</a>, <a href="https://creativecommons.org/licenses/by/2.0/de/" target="_blank">CC-BY 2.0</a>