Pius X, P. (1904). The XIII Centenary of St. Gregory, Encyclical Letter of Pius X. New York.
Chicago Style (17. basım) AtıfPius X, Pope. The XIII Centenary of St. Gregory, Encyclical Letter of Pius X. New York, 1904.
MLA (8th ed.) AtıfPius X, Pope. The XIII Centenary of St. Gregory, Encyclical Letter of Pius X. New York, 1904.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..