MLA
Four African American Boys Sitting on a Wooden Box Outdoors and Eating Watermelon. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/1741rn8pnt-cor.
APA, 6th edition
Four African American boys sitting on a wooden box outdoors and eating watermelon (Box 69). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/1741rn8pnt-cor.
Chicago
“Four African American Boys Sitting on a Wooden Box Outdoors and Eating Watermelon.” Photographic postcards. Robert Langmuir African American Photograph Collection, n.d. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/1741rn8pnt-cor.