MLA
Osborne Publ. Co. (New York, N.Y.). The Cake Walkers-- Young's Pier, Atlantic City, U.S.A. : African American men and women in costume dancing the cakewalk on Young's Pier, in Atlantic City, New Jersey. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/4644qrfjbq-cor.
APA, 6th edition
Osborne Publ. Co. (New York, N.Y.). (unknown)[The Cake Walkers-- Young's Pier, Atlantic City, U.S.A. : African American men and women in costume dancing the cakewalk on Young's Pier, in Atlantic City, New Jersey]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/4644qrfjbq-cor.
Chicago
Osborne Publ. Co. (New York, N.Y.), The Cake Walkers-- Young's Pier, Atlantic City, U.S.A. : African American men and women in costume dancing the cakewalk on Young's Pier, in Atlantic City, New Jersey, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/4644qrfjbq-cor.