MLA
Envelope Containing Address of Mary Marshall, the Mother of Michael Marshall. 1884. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 23, Folder 20. https://digital.library.emory.edu/purl/989r2281t4-cor.
APA, 6th edition
Envelope containing address of Mary Marshall, the mother of Michael Marshall (Box 23, Folder 20). (1884). [Envelopes]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/989r2281t4-cor.
Chicago
“Envelope Containing Address of Mary Marshall, the Mother of Michael Marshall.” Envelopes. Civil War Collection, 1884. Box 23, Folder 20. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/989r2281t4-cor.