MLA
Wolfe, P. A. At the Old City Gates, St. Augustine, Florida, the Oldest City in the United States. 1930. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 75. https://digital.library.emory.edu/purl/9354f4qrhw-cor.
APA, 6th edition
Wolfe, P. A. (1930). At the old city gates, St. Augustine, Florida, the oldest city in the United States (Box 75) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/9354f4qrhw-cor.
Chicago
Wolfe, P. A. “At the Old City Gates, St. Augustine, Florida, the Oldest City in the United States.” Postcards. Robert Langmuir African American Photograph Collection, 1930. Box 75. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/9354f4qrhw-cor.