MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Full length group of three; black woman seated with white child in lap, white boy stands with hand on her shoulder. Cased tintype, quarter plate. Box 6, folder 77. circa 1875. https://collections.library.yale.edu/catalog/2002134.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 6, folder 77"])(circa 1875)[Unknown photographer Full length group of three; black woman seated with white child in lap, white boy stands with hand on her shoulder. Cased tintype, quarter plate]. https://collections.library.yale.edu/catalog/2002134.