MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Full length portrait of cavalry soldier standing; felt hat quarter creased, riding crop in right hand. Photographic postcard. Box 25. circa 1914. https://collections.library.yale.edu/catalog/2042475.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 25"])(circa 1914)[Unknown photographer Full length portrait of cavalry soldier standing; felt hat quarter creased, riding crop in right hand. Photographic postcard]. https://collections.library.yale.edu/catalog/2042475.