MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Cavalry troop passes along narrow dirt road with house and hill in background. Photographic postcard. Box 25. circa 1918. https://collections.library.yale.edu/catalog/16172749.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 25"])(circa 1918)[Unknown photographer Cavalry troop passes along narrow dirt road with house and hill in background. Photographic postcard]. https://collections.library.yale.edu/catalog/16172749.