MLA
Billy Gardner's Piccaninny's Posing with Various Musical Instruments inside Billy Gardner's Restaurant, in Milford, Connecticut. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 70. https://digital.library.emory.edu/purl/996k0p2nmc-cor.
APA, 6th edition
Billy Gardner's Piccaninny's posing with various musical instruments inside Billy Gardner's restaurant, in Milford, Connecticut (Box 70). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/996k0p2nmc-cor.
Chicago
“Billy Gardner's Piccaninny's Posing with Various Musical Instruments inside Billy Gardner's Restaurant, in Milford, Connecticut.” Photographic postcards. Robert Langmuir African American Photograph Collection, n.d. Box 70. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/996k0p2nmc-cor.