[Photograph of two unidentified men outside]
MLA
[Photograph of Two Unidentified Men Outside]. 0AD. https://collections.library.yale.edu/catalog/2011070.
APA, 6th edition
[Photograph of two unidentified men outside]. (0 C.E.). [Card photographs, Cartes-de-visite, Photographic prints, Photographs, Studio portraits]. https://collections.library.yale.edu/catalog/2011070.