MLA
Thompson, C. H. An African American Boy Sitting on a Small Wagon Being Pulled by a Goat on a Cobblestone Street with a Building with a Metal Fence behind Him. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 68. https://digital.library.emory.edu/purl/0171vhhmkh-cor.
APA, 6th edition
Thompson, C. H. An African American boy sitting on a small wagon being pulled by a goat on a cobblestone street with a building with a metal fence behind him (Box 68) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/0171vhhmkh-cor.
Chicago
Thompson, C. H. “An African American Boy Sitting on a Small Wagon Being Pulled by a Goat on a Cobblestone Street with a Building with a Metal Fence behind Him.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 68. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/0171vhhmkh-cor.