MLA
Portrait of William M. Trotter and Friend. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 15. https://digital.library.emory.edu/purl/532d7wm3g5-cor.
APA, 6th edition
Portrait of William M. Trotter and friend (Box 15). [Card photographs (photographs)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/532d7wm3g5-cor.
Chicago
“Portrait of William M. Trotter and Friend.” Card photographs (photographs). Robert Langmuir African American Photograph Collection, n.d. Box 15. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/532d7wm3g5-cor.