APA (7th ed.) Zitazioa
Twain, M. (2001). Political economy. Alex Catalogue.
Chicago Style (17th ed.) Zitazioa
Twain, Mark. Political Economy. Raleigh, NC: Alex Catalogue, 2001.
MLA (9th ed.) Zitazioa
Twain, Mark. Political Economy. Alex Catalogue, 2001.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.