MLA
Knaffl & Bro. (Knoxville, Tenn.). Your next move : six African American children sitting on a cart with an old man pushing it and another man holding a baby : with a dog in the front. 1899 approx.. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/569z08kpv3-cor.
APA, 6th edition
Knaffl & Bro. (Knoxville, Tenn.). (1899 approx.)[Your next move : six African American children sitting on a cart with an old man pushing it and another man holding a baby : with a dog in the front]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/569z08kpv3-cor.
Chicago
Knaffl & Bro. (Knoxville, Tenn.), Your next move : six African American children sitting on a cart with an old man pushing it and another man holding a baby : with a dog in the front, 1899 approx., Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/569z08kpv3-cor.