MLA
African American Soldier Firing a Large Machine Gun, with a Group of Soldiers Standing behind Him. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 70. https://digital.library.emory.edu/purl/692t4b8gzm-cor.
APA, 6th edition
African American soldier firing a large machine gun, with a group of soldiers standing behind him (Box 70). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/692t4b8gzm-cor.
Chicago
“African American Soldier Firing a Large Machine Gun, with a Group of Soldiers Standing behind Him.” 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/692t4b8gzm-cor.