Catholic Church. Pope (1878-1903 : Leo XIII) & Leo XIII, P. (1902). Apostolical Letter of Our Most Holy Lord Leo XIII by Divine Providence Pope =: Sanctissimi Domini Nostri Leonis divina providentia Papae XIII. Littera Apostolica. Apostleship of Prayer.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Catholic Church. Pope (1878-1903 : Leo XIII) و Pope Leo XIII. Apostolical Letter of Our Most Holy Lord Leo XIII by Divine Providence Pope =: Sanctissimi Domini Nostri Leonis Divina Providentia Papae XIII. Littera Apostolica. New York, N.Y.: Apostleship of Prayer, 1902.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Catholic Church. Pope (1878-1903 : Leo XIII) و Pope Leo XIII. Apostolical Letter of Our Most Holy Lord Leo XIII by Divine Providence Pope =: Sanctissimi Domini Nostri Leonis Divina Providentia Papae XIII. Littera Apostolica. Apostleship of Prayer, 1902.