Foto: "<a href="https://ccnull.de/foto/christmas-decor-balls-and-branches-of-a-christmas-tree-on-a-black-background-with-a-medical-mask/1018292" target="_blank">Christmas decor, balls and branches of a Christmas tree on a black background with a medical mask</a>" von <a href="https://ccnull.de/fotograf/marco-verch" target="_blank">Marco Verch</a> via <a href="https://ccnull.de" target="_blank">ccnull.de</a> - <a href="https://www.flickr.com/photos/30478819@N08/50383688013/" target="_blank">Bildquelle</a>, <a href="https://creativecommons.org/licenses/by/2.0/de/" target="_blank">CC-BY 2.0</a>