Pius, P. C. C. P. (1907). Litterae Encyclicae...De Modernistarum Doctrinis. Philadelphia.
Chicago Style (17th ed.) CitationPius, Pope; Catholic Church. Pope. Litterae Encyclicae...De Modernistarum Doctrinis. Philadelphia, 1907.
MLA (8th ed.) CitationPius, Pope; Catholic Church. Pope. Litterae Encyclicae...De Modernistarum Doctrinis. Philadelphia, 1907.
Warning: These citations may not always be 100% accurate.