O'Brien, D. J. (1992). Isaac Hecker: An American Catholic. Paulist Press.
Lua i Stíl Chicago (17ú heag.)O'Brien, David J. Isaac Hecker: An American Catholic. New York: Paulist Press, 1992.
Lua MLA (8ú heag.)O'Brien, David J. Isaac Hecker: An American Catholic. Paulist Press, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.