MLA
Son, D. Murphy's. Union Patriotic Envelopes - "The Southern Vulture 'Hard up.'" Published by D. Murphy's Son. D. Murphy's Son, Print, 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 21, Folder 9. https://digital.library.emory.edu/purl/525k98sgdq-cor.
APA, 6th edition
Son, D. M. (1861). Union patriotic envelopes - "The Southern Vulture 'hard up.'" Published by D. Murphy's Son (Box 21, Folder 9) [Envelopes]. D. Murphy's Son, Print; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/525k98sgdq-cor.
Chicago
Son, D. Murphy's. “Union Patriotic Envelopes - ‘The Southern Vulture 'Hard up.'" Published by D. Murphy's Son.” Envelopes. Civil War Collection. New York City, NY: D. Murphy's Son, Print, 1861. Box 21, Folder 9. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/525k98sgdq-cor.