MLA
Co., E. C. Kropp. Picking Cotton : down in Sunny Dixie. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 68. https://digital.library.emory.edu/purl/296wwpzgqk-cor.
APA, 6th edition
Co., E. C. K. Picking cotton : down in sunny Dixie (Box 68) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/296wwpzgqk-cor.
Chicago
Co., E. C. Kropp. “Picking Cotton : down in Sunny Dixie.” 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/296wwpzgqk-cor.