»Anshen, R.N. (1967). Prologue. My Search for Absolutes. By Paul Tillich. New York: Touchstone/Simon and Schuster, Inc. 19-22. Aquinas, T. (1948). Whether God exists? The Summa Theologica, Q.2., Art. 3, Introduction to Saint Thomas Aquinas, ed. A.C. Pegis. New York: The Modern Library.
Armbruster, C.J. (1967). The vision of Paul Tillich. New York: Sheed & Ward.
Cobb, J.B., Jr. (1986). Living options in Protestant theology: a survey of methods. Lanham, Md.: University Press of America.
Freemantle, A. (1954). The Age of Belief: The Medieval Philosophers. A Mentor Book. New York: NAL.
Griffin, D. (1983). Barth: much ado about nothingness. God, Power and Evil. Ann Arbor, Michigan: AAR. 150-173.
Griffin, D.R. (1990). A process christology. New Y