MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Group of five soldiers before tent. Pre-WW I uniforms with strapped canvas puttees, and narrow visored caps; one wears a felt hat with a light colored band; two wear sidearms; one holds a baton. Photographic postcard. Box 25. circa 1910. https://collections.library.yale.edu/catalog/16172731.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 25"])(circa 1910)[Unknown photographer Group of five soldiers before tent. Pre-WW I uniforms with strapped canvas puttees, and narrow visored caps; one wears a felt hat with a light colored band; two wear sidearms; one holds a baton. Photographic postcard]. https://collections.library.yale.edu/catalog/16172731.