MLA
Howe, F. L. Greetings from Atlanta, Ga. : Nigger Heben ; Cotton Fields. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/023vt4b8kn-cor.
APA, 6th edition
Howe, F. L. Greetings from Atlanta, Ga. : Nigger Heben ; Cotton fields (Box 69) [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/023vt4b8kn-cor.
Chicago
Howe, F. L. “Greetings from Atlanta, Ga. : Nigger Heben ; Cotton Fields.” Photographic postcards. Robert Langmuir African American Photograph Collection, n.d. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/023vt4b8kn-cor.