APA (7th ed.) Zitazioa
Willett, C. (2014). Interspecies ethic. Columbia University Press.
Chicago Style (17th ed.) Zitazioa
Willett, Cynthia. Interspecies Ethic. New York: Columbia University Press, 2014.
MLA (9th ed.) Zitazioa
Willett, Cynthia. Interspecies Ethic. Columbia University Press, 2014.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.