MLA
Two African American Men Sitting on a Bench and Two Standing behind Them, All Wearing Suits. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/2085hqbzns-cor.
APA, 6th edition
Two African American men sitting on a bench and two standing behind them, all wearing suits (Box 72). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2085hqbzns-cor.
Chicago
“Two African American Men Sitting on a Bench and Two Standing behind Them, All Wearing Suits.” 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/2085hqbzns-cor.