Karte der Straßenbahnen der Stadt Berlin
<a href="https://de.wikipedia.org/wiki/User:Chumwa" class="extiw" title="de:User:Chumwa">Maximilian Dörrbecker</a> (<a href="https://de.wikipedia.org/wiki/User:Chumwa" class="extiw" title="de:User:Chumwa">Chumwa</a>)
CC BY-SA 2.5
<span class="int-own-work" lang="en">Own work</span>, using a <a href="//commons.wikimedia.org/wiki/File:Baedeker,_Gro%C3%9Fer_Streifenplan_von_Berlin,_1914.jpg" title="File:Baedeker, Großer Streifenplan von Berlin, 1914.jpg">1914 Baedeker map</a> as background