MLA
Wyon, Joseph S. Great Seal of the Confederacy, Electrotype Replica Created by Attorney John T. Pickett in 1872. Original Was Engraved by Joseph S. Wyon of London in 1864. 1864. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 11, Folder 12. https://digital.library.emory.edu/purl/887brv16hb-cor.
APA, 6th edition
Wyon, J. S. (1864). Great Seal of the Confederacy, electrotype replica created by attorney John T. Pickett in 1872. Original was engraved by Joseph S. Wyon of London in 1864 (Box 11, Folder 12) [Medals]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/887brv16hb-cor.
Chicago
Wyon, Joseph S. “Great Seal of the Confederacy, Electrotype Replica Created by Attorney John T. Pickett in 1872. Original Was Engraved by Joseph S. Wyon of London in 1864.” Medals. Civil War Collection, 1864. Box 11, Folder 12. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/887brv16hb-cor.