MLA
A Horseless Carriage : Two African American Boys in a Small Carriage. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/12683bk3kx-cor.
APA, 6th edition
A horseless carriage : two African American boys in a small carriage (Box 72). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/12683bk3kx-cor.
Chicago
“A Horseless Carriage : Two African American Boys in a Small Carriage.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/12683bk3kx-cor.