Willis, F. R. (1987). Western civilization: A belief introduction. Macmillan.
Lua i Stíl Chicago (17ú heag.)Willis, F. Roy. Western Civilization: A Belief Introduction. New York: Macmillan, 1987.
Lua MLA (9ú heag.)Willis, F. Roy. Western Civilization: A Belief Introduction. Macmillan, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.