MLA
A Black Guard : a Line of African American Men and Boys. 1908. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/6623bk3jck-cor.
APA, 6th edition
A black guard : a line of African American men and boys (Box 72). (1908). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6623bk3jck-cor.
Chicago
“A Black Guard : a Line of African American Men and Boys.” Postcards. Robert Langmuir African American Photograph Collection, 1908. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6623bk3jck-cor.