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.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Pius XI, Pope, و 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.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Pius XI, Pope, و James D. Loeffler. Directives for Catholic Action: Expounded by Pope Pius XI ; with Indulgences for Those Enrolled in Catholic Action. Central Bureau Press, 1938.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.