Cite

[Photograph of an unidentified soldier]

MLA

McClees. [Photograph of an Unidentified Soldier]. 0AD. https://collections.library.yale.edu/catalog/2011007.

APA, 6th edition

M. C. (0 C.E.). [Photograph of an unidentified soldier] [Card photographs, Cartes-de-visite, Photographic prints, Photographs, Studio portraits]. https://collections.library.yale.edu/catalog/2011007.