Cite

[Photograph of several men unloading a boat, one man walks with a heavy sack]

MLA

[Photograph of Several Men Unloading a Boat, One Man Walks with a Heavy Sack]. 1950. https://collections.library.yale.edu/catalog/2067775.

APA, 6th edition

[Photograph of several men unloading a boat, one man walks with a heavy sack]. (1950). [Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2067775.