O'Malley, J. W. (1958). Challenge. Loyola University Press.
Lua i Stíl Chicago (17ú heag.)O'Malley, John W. Challenge. Chicago: Loyola University Press, 1958.
Lua MLA (8ú heag.)O'Malley, John W. Challenge. Loyola University Press, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.