Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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