MLA
Mitchell, Edward H. In the Good Old Summer Time. 1905. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/5053ffbgbn-cor.
APA, 6th edition
Mitchell, E. H. (1905). In the good old summer time (Box 69) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/5053ffbgbn-cor.
Chicago
Mitchell, Edward H. “In the Good Old Summer Time.” Postcards. Robert Langmuir African American Photograph Collection, 1905. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/5053ffbgbn-cor.