Kreeft, P. (1988). Fundamentals of the faith: Essays in Christian apologetics. Ignatius.
Lua i Stíl Chicago (17ú heag.)Kreeft, Peter. Fundamentals of the Faith: Essays in Christian Apologetics. San Francisco: Ignatius, 1988.
Lua MLA (9ú heag.)Kreeft, Peter. Fundamentals of the Faith: Essays in Christian Apologetics. Ignatius, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.