APA (7th ed.) Citation

Drewermann, E., & Krieger, D. J. (1991). Open heavens: : meditations for Advent and Christmas. Orbis Books.

Chicago Style (17th ed.) Citation

Drewermann, Eugen, and David J. Krieger. Open Heavens: : Meditations for Advent and Christmas. New York: Orbis Books, 1991.

MLA (9th ed.) Citation

Drewermann, Eugen, and David J. Krieger. Open Heavens: : Meditations for Advent and Christmas. Orbis Books, 1991.