Purwatma, M. (1990). The explanation of the mystery of the Trinity based on the attribute of God as supreme love: A study on the "De Trinitate" of Richard of St. Victor. Pontificia Universitas Urbaniana, Facultas Theologica.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Purwatma, Matheus. The Explanation of the Mystery of the Trinity Based on the Attribute of God as Supreme Love: A Study on the "De Trinitate" of Richard of St. Victor. Romae: Pontificia Universitas Urbaniana, Facultas Theologica, 1990.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Purwatma, Matheus. The Explanation of the Mystery of the Trinity Based on the Attribute of God as Supreme Love: A Study on the "De Trinitate" of Richard of St. Victor. Pontificia Universitas Urbaniana, Facultas Theologica, 1990.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.