MLA
Mangold, J. G. (Jonas G.), 1826-1894. Boy dress in military uniform, wearing a sword, holding a cigar up by his mouth, with his left hand on his hip. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/945cc2fr4f-cor.
APA, 6th edition
Mangold, J. G. (Jonas G.), 1826-1894. (unknown)[Boy dress in military uniform, wearing a sword, holding a cigar up by his mouth, with his left hand on his hip]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/945cc2fr4f-cor.
Chicago
Mangold, J. G. (Jonas G.), 1826-1894, Boy dress in military uniform, wearing a sword, holding a cigar up by his mouth, with his left hand on his hip, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/945cc2fr4f-cor.