MLA
William Warren Johnson, an African American Soldier Wearing a Uniform, Holding a Firearm. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 70. https://digital.library.emory.edu/purl/344pk0p2rs-cor.
APA, 6th edition
William Warren Johnson, an African American soldier wearing a uniform, holding a firearm (Box 70). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/344pk0p2rs-cor.
Chicago
“William Warren Johnson, an African American Soldier Wearing a Uniform, Holding a Firearm.” 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/344pk0p2rs-cor.