MLA
Richter & Co. Art Studio (Philadelphia, Pa.). Portrait of J.M. Roulson. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/003cz8w9k9-cor.
APA, 6th edition
Richter & Co. Art Studio (Philadelphia, Pa.). (unknown)[Portrait of J.M. Roulson]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/003cz8w9k9-cor.
Chicago
Richter & Co. Art Studio (Philadelphia, Pa.), Portrait of J.M. Roulson, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/003cz8w9k9-cor.