MLA
Krebbs, S. H., and Co. Two African American Men Picking Cotton in a Field, in Helena, Arkansas. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 68. https://digital.library.emory.edu/purl/8708w9gj1d-cor.
APA, 6th edition
Krebbs, S. H., & C. Two African American men picking cotton in a field, in Helena, Arkansas (Box 68) [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/8708w9gj1d-cor.
Chicago
Krebbs, S. H., and Co. “Two African American Men Picking Cotton in a Field, in Helena, Arkansas.” Photographic 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/8708w9gj1d-cor.