MLA

Simpson, Randolph Linsly, 1927-1992. C.F. O'Keefe, Fort Madison, IA Three quarter length portrait, man in frock coat standing, arm on draped parapet, holding walking stick behind back. Cabinet photograph. Box 9, folder 258. circa 1880. https://collections.library.yale.edu/catalog/2002310.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 9, folder 258"])(circa 1880)[C.F. O'Keefe, Fort Madison, IA Three quarter length portrait, man in frock coat standing, arm on draped parapet, holding walking stick behind back. Cabinet photograph]. https://collections.library.yale.edu/catalog/2002310.