APA (7th ed.) Zitazioa
Willis, F. R. (1977). Western civilization: An urban perspective (2nd.ed.). D.C.Heath and Co..
Chicago Style (17th ed.) Zitazioa
Willis, F. Roy. Western Civilization: An Urban Perspective. 2nd.ed. Lexington Massachusetts: D.C.Heath and Co., 1977.
MLA (9th ed.) Zitazioa
Willis, F. Roy. Western Civilization: An Urban Perspective. 2nd.ed. D.C.Heath and Co., 1977.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.