MLA
Howe, F. L. My Turn next : Seven African American Boys at a Fence, with One's Head in a Barrel. 1906. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/8601zcrjgr-cor.
APA, 6th edition
Howe, F. L. (1906). My turn next : seven African American boys at a fence, with one's head in a barrel (Box 72) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/8601zcrjgr-cor.
Chicago
Howe, F. L. “My Turn next : Seven African American Boys at a Fence, with One's Head in a Barrel.” Postcards. Robert Langmuir African American Photograph Collection, 1906. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/8601zcrjgr-cor.