Tillich, P., & Gomes, P. J. (2000). The courage to be (2nd ed.). Yale University Press.
Cita Chicago (17th ed.)Tillich, Paul, i Peter J. Gomes. The Courage to Be. 2nd ed. New Haven: Yale University Press, 2000.
Cita MLA (9th ed.)Tillich, Paul, i Peter J. Gomes. The Courage to Be. 2nd ed. Yale University Press, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.