MLA
Co., E. C. Kropp. Down in Sunny Dixie : an African American Boy Eating a Watermelon. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/6386hdr7x2-cor.
APA, 6th edition
Co., E. C. K. Down in sunny Dixie : an African American boy eating a watermelon (Box 69) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6386hdr7x2-cor.
Chicago
Co., E. C. Kropp. “Down in Sunny Dixie : an African American Boy Eating a Watermelon.” 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/6386hdr7x2-cor.