Pius, P. C. C. P. (1937). On the religious situation in Mexico, apostolic letter of His Holiness, Pope Pius XI, issued March 28, 1937. Washington, D.C..
Chicago-viite (17. p.)Pius, Pope; Catholic Church. Pope. On the Religious Situation in Mexico, Apostolic Letter of His Holiness, Pope Pius XI, Issued March 28, 1937. Washington, D.C., 1937.
MLA-viite (8. p.)Pius, Pope; Catholic Church. Pope. On the Religious Situation in Mexico, Apostolic Letter of His Holiness, Pope Pius XI, Issued March 28, 1937. Washington, D.C., 1937.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.