MLA
Sheppard, William, -1675?. Mistakes of Dr. W.E.B. Du Bois : being an answer to Dr. W.E.B. Du Bois' attack upon the Honorable Marcus Garvey. 1921. African American Imprints Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/460qrfj7qh-cor.
APA, 6th edition
Sheppard, William, -1675?. (1921)[Mistakes of Dr. W.E.B. Du Bois : being an answer to Dr. W.E.B. Du Bois' attack upon the Honorable Marcus Garvey]. African American Imprints Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/460qrfj7qh-cor.
Chicago
Sheppard, William, -1675?, Mistakes of Dr. W.E.B. Du Bois : being an answer to Dr. W.E.B. Du Bois' attack upon the Honorable Marcus Garvey, 1921, African American Imprints Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/460qrfj7qh-cor.