MLA

Simpson, Randolph Linsly, 1927-1992. Studio unknown Group portrait, five men and four women in formal dress; possibly a singing group. Cabinet photograph. Box 9, folder 166. circa 1875. https://collections.library.yale.edu/catalog/2002218.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 9, folder 166"])(circa 1875)[Studio unknown Group portrait, five men and four women in formal dress; possibly a singing group. Cabinet photograph]. https://collections.library.yale.edu/catalog/2002218.