MLA
Valentine, and Sons. Phosphate Mining, Florida [Hand Colored]. 1909. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 71. https://digital.library.emory.edu/purl/293gxd257r-cor.
APA, 6th edition
V., & S. (1909). Phosphate mining, Florida [hand colored] (Box 71) [Photographic postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/293gxd257r-cor.
Chicago
Valentine, and Sons. “Phosphate Mining, Florida [Hand Colored].” Photographic postcards. Robert Langmuir African American Photograph Collection, 1909. Box 71. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/293gxd257r-cor.