APA (7th ed.) Zitazioa
Barna, G. (1991). What Americans believe: An annual survey of values and religious views in the United States. Regal Books.
Chicago Style (17th ed.) Zitazioa
Barna, George. What Americans Believe: An Annual Survey of Values and Religious Views in the United States. California: Regal Books, 1991.
MLA (9th ed.) Zitazioa
Barna, George. What Americans Believe: An Annual Survey of Values and Religious Views in the United States. Regal Books, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.