APA (7th ed.) Zitazioa
O'Brien, G. (2001). An Essay on mediæval economic teaching. Batoche.
Chicago Style (17th ed.) Zitazioa
O'Brien, George. An Essay on Mediæval Economic Teaching. Kitchener, Ont.: Batoche, 2001.
MLA (9th ed.) Zitazioa
O'Brien, George. An Essay on Mediæval Economic Teaching. Batoche, 2001.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.