APA (7e ed.) Bronvermelding

Pius XI, P., & Loeffler, J. D. (1938). Directives for Catholic action: Expounded by Pope Pius XI ; with indulgences for those enrolled in Catholic action. Central Bureau Press.

Chicago (17e ed.) Bronvermelding

Pius XI, Pope, en James D. Loeffler. Directives for Catholic Action: Expounded by Pope Pius XI ; with Indulgences for Those Enrolled in Catholic Action. St. Louis, Mo.: Central Bureau Press, 1938.

MLA (8e ed.) Bronvermelding

Pius XI, Pope, en James D. Loeffler. Directives for Catholic Action: Expounded by Pope Pius XI ; with Indulgences for Those Enrolled in Catholic Action. Central Bureau Press, 1938.