APA (7th ed.) Zitazioa
Friedrich, P. (1970). Proto-indo-european trees: The arboreal system of a prehistoric people. University of Chicago Press.
Chicago Style (17th ed.) Zitazioa
Friedrich, Paul. Proto-indo-european Trees: The Arboreal System of a Prehistoric People. Chicago: University of Chicago Press, 1970.
MLA (9th ed.) Zitazioa
Friedrich, Paul. Proto-indo-european Trees: The Arboreal System of a Prehistoric People. University of Chicago Press, 1970.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.