APA (7th ed.) Citation

Pennington, M. B. (1990). Call to the center: The Gospel's invitation to deeper prayer. Image Books.

Chicago Style (17th ed.) Citation

Pennington, M. Basil. Call to the Center: The Gospel's Invitation to Deeper Prayer. New York: Image Books, 1990.

MLA (9th ed.) Citation

Pennington, M. Basil. Call to the Center: The Gospel's Invitation to Deeper Prayer. Image Books, 1990.