MLA
Blanche, One of the Guides, at the Lewis Plantation, Brooksville, Fla. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 74. https://digital.library.emory.edu/purl/84302v6x0m-cor.
APA, 6th edition
Blanche, one of the guides, at the Lewis Plantation, Brooksville, Fla. (Box 74). [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/84302v6x0m-cor.
Chicago
“Blanche, One of the Guides, at the Lewis Plantation, Brooksville, Fla.” Photographic postcards. Robert Langmuir African American Photograph Collection, n.d. Box 74. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/84302v6x0m-cor.