Catholic Church. Pope (1922-1939 : Pius XI), National Catholic Welfare Conference, & Pius XI, P. (1937). On the religious situation in Mexico: Apostolic letter of His Holiness, Pope Pius XI, issued March 28, 1937. National Catholic Welfare Conference.
Chicago-referens (17:e uppl.)Catholic Church. Pope (1922-1939 : Pius XI), National Catholic Welfare Conference, och Pope Pius XI. On the Religious Situation in Mexico: Apostolic Letter of His Holiness, Pope Pius XI, Issued March 28, 1937. Washington, D.C.: National Catholic Welfare Conference, 1937.
MLA-referens (8:e uppl.)Catholic Church. Pope (1922-1939 : Pius XI), et al. On the Religious Situation in Mexico: Apostolic Letter of His Holiness, Pope Pius XI, Issued March 28, 1937. National Catholic Welfare Conference, 1937.