Wikimedia | Crain's Philadelphia
Photo Credit URL: 
https://commons.wikimedia.org/wiki/File:San_Francisco_Cable_Car_on_California_Street.jpg
Image: 
Photographer: 
Fred Hsu
Photographer URL: 
https://en.wikipedia.org/wiki/User:Fred_Hsu
Attribution Type: 
GNU Free Documentation License
Attribution Type URL: 
https://en.wikipedia.org/wiki/GNU_Free_Documentation_License