Cite

20th U.S. Infantry camp--guard mount

MLA

Hecox, Frank C. 20th U.S. Infantry Camp--Guard Mount. 0AD. https://collections.library.yale.edu/catalog/2015344.

APA, 6th edition

Hecox, F. C. (0 C.E.). 20th U.S. Infantry camp--guard mount [Photographic postcards, Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2015344.