MLA
Sargent (Boston, Mass.). African American man. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/815p8cz942-cor.
APA, 6th edition
Sargent (Boston, Mass.). (unknown)[African American man]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/815p8cz942-cor.
Chicago
Sargent (Boston, Mass.), African American man, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/815p8cz942-cor.