MLA
Co., E. C. Kropp. Unloading Green Turtles at Key West, Fla. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/484mkkwhbb-cor.
APA, 6th edition
Co., E. C. K. Unloading green turtles at Key West, Fla. (Box 69) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/484mkkwhbb-cor.
Chicago
Co., E. C. Kropp. “Unloading Green Turtles at Key West, Fla.” 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/484mkkwhbb-cor.