Mexican workers standing in front of bus. The bus, in background, is labeled Pacific Greyhound Line

Chicago citation style
Higgins, Floyd Halleck, 1886-1975, Photographer. Mexican workers standing in front of bus. The bus, in background, is labeled Pacific Greyhound Line. 1942-09-00. Retrieved from the Digital Public Library of America, http://ark.cdlib.org/ark:/13030/kt6f59s0gw. (Accessed August 16, 2018.)
APA citation style
Higgins, Floyd Halleck, 1886-1975, Photographer, (1942-09-00) Mexican workers standing in front of bus. The bus, in background, is labeled Pacific Greyhound Line. Retrieved from the Digital Public Library of America, http://ark.cdlib.org/ark:/13030/kt6f59s0gw
MLA citation style
Higgins, Floyd Halleck, 1886-1975, Photographer. Retrieved from the Digital Public Library of America <http://ark.cdlib.org/ark:/13030/kt6f59s0gw>.
Note: These citations are programmatically generated and may be incomplete.