Cite

[Photograph of an unknown man in tall boots, a hat, and a gun and holster]

MLA

[Photograph of an Unknown Man in Tall Boots, a Hat, and a Gun and Holster]. 0AD. https://collections.library.yale.edu/catalog/2014106.

APA, 6th edition

[Photograph of an unknown man in tall boots, a hat, and a gun and holster]. (0 C.E.). [Photographic prints, Photographs, Snapshots]. https://collections.library.yale.edu/catalog/2014106.