MLA
Mitchell. African American Man Sitting on the Arm of a Chair with His Legs Crossed, While Wearing a Suit and Hat, Holding a Pair of Gloves and a Cane. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/979h44j123-cor.
APA, 6th edition
M. African American man sitting on the arm of a chair with his legs crossed, while wearing a suit and hat, holding a pair of gloves and a cane (Box 72) [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/979h44j123-cor.
Chicago
Mitchell. “African American Man Sitting on the Arm of a Chair with His Legs Crossed, While Wearing a Suit and Hat, Holding a Pair of Gloves and a Cane.” Photographic postcards. Robert Langmuir African American Photograph Collection, n.d. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/979h44j123-cor.