MLA
Yum! Yum! : Watermelon : and African American Boy Eating Watermelon. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/829b5mkm13-cor.
APA, 6th edition
Yum! Yum! : watermelon : and African American boy eating watermelon (Box 69). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/829b5mkm13-cor.
Chicago
“Yum! Yum! : Watermelon : and African American Boy 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/829b5mkm13-cor.