Catholic Church. Pope. (1891). Encyclical letter of our Holy Father by divine providence Pope Leo XIII on the condition of labor. Baltimore, MD: John Murphy & Co..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Catholic Church. Pope. Encyclical Letter of Our Holy Father by Divine Providence Pope Leo XIII on the Condition of Labor. Baltimore, MD: John Murphy & Co., 1891.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Catholic Church. Pope. Encyclical Letter of Our Holy Father by Divine Providence Pope Leo XIII on the Condition of Labor. Baltimore, MD: John Murphy & Co., 1891.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.