Cite

[Photograph of two men with rifles walking through a snowy valley]

MLA

[Photograph of Two Men with Rifles Walking through a Snowy Valley]. 1915. https://collections.library.yale.edu/catalog/11683462.

APA, 6th edition

[Photograph of two men with rifles walking through a snowy valley]. (1915). [Photographs, Slides (glass)]. https://collections.library.yale.edu/catalog/11683462.