Cite

[No. 65: Photograph of two men sliding down snowy slope]

MLA

[No. 65: Photograph of Two Men Sliding down Snowy Slope]. 1915. https://collections.library.yale.edu/catalog/11679665.

APA, 6th edition

[No. 65: Photograph of two men sliding down snowy slope]. (1915). [Photographs, Slides (glass)]. https://collections.library.yale.edu/catalog/11679665.