Cite

[Photograph of three pack mules walking down the street while heavily laden]

MLA

[Photograph of Three Pack Mules Walking down the Street While Heavily Laden]. 1950. https://collections.library.yale.edu/catalog/2067773.

APA, 6th edition

[Photograph of three pack mules walking down the street while heavily laden]. (1950). [Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2067773.