MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Group portrait of six; four men in uniform; one man, one woman in civilian dress. Photographic postcard. Box 25. circa 1917. https://collections.library.yale.edu/catalog/16172736.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 25"])(circa 1917)[Unknown photographer Group portrait of six; four men in uniform; one man, one woman in civilian dress. Photographic postcard]. https://collections.library.yale.edu/catalog/16172736.