MLA
Holt, Harold. Paul Robeson in a Suit Leaning out of a Train Window Holding a Hat in His Hand. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21. https://digital.library.emory.edu/purl/7956djhb8s-cor.
APA, 6th edition
Holt, H. Paul Robeson in a suit leaning out of a train window holding a hat in his hand (Box 21) [Black-and-white photographs]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7956djhb8s-cor.
Chicago
Holt, Harold. “Paul Robeson in a Suit Leaning out of a Train Window Holding a Hat in His Hand.” Black-and-white photographs. Langmuir Deposit - Sept 2020, n.d. Box 21. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/7956djhb8s-cor.