Cite

Unknown photographer Full length portrait, man seated in derby hat, holding bunch of keys. Later 19th century photograph, framed. 6-1/2 x 6.

MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Full length portrait, man seated in derby hat, holding bunch of keys. Later 19th century photograph, framed. 6-1/2 x 6.. Box 16, folder 758. circa 1864. https://collections.library.yale.edu/catalog/2042503.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 16, folder 758"])(circa 1864)[Unknown photographer Full length portrait, man seated in derby hat, holding bunch of keys. Later 19th century photograph, framed. 6-1/2 x 6.]. https://collections.library.yale.edu/catalog/2042503.