APA (7th ed.) Zitazioa
Douglass, F., & Ruffin, G. L. (2001). The life and times of Frederick Douglass. Digital Scanning.
Chicago Style (17th ed.) Zitazioa
Douglass, Frederick, eta George L. Ruffin. The Life and Times of Frederick Douglass. Scituate, Mass.: Digital Scanning, 2001.
MLA (9th ed.) Zitazioa
Douglass, Frederick, eta George L. Ruffin. The Life and Times of Frederick Douglass. Digital Scanning, 2001.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.