Pius, P. C. C. P. (1930). Encyclical Letter of His Holiness Pius XI By Divine Providence Pope. The Vatican.
Chicago Style (17th ed.) CitationPius, Pope; Catholic Church. Pope. Encyclical Letter of His Holiness Pius XI By Divine Providence Pope. The Vatican, 1930.
MLA (8th ed.) CitationPius, Pope; Catholic Church. Pope. Encyclical Letter of His Holiness Pius XI By Divine Providence Pope. The Vatican, 1930.
Warning: These citations may not always be 100% accurate.