MLA
Jack Johnson, Heavyweight Champion of the World. 1911. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 74. https://digital.library.emory.edu/purl/13331zcrmr-cor.
APA, 6th edition
Jack Johnson, heavyweight champion of the world (Box 74). (1911). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/13331zcrmr-cor.
Chicago
“Jack Johnson, Heavyweight Champion of the World.” Postcards. Robert Langmuir African American Photograph Collection, 1911. Box 74. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/13331zcrmr-cor.