APA (7th ed.) Citation

Merton, T., & Hanh, T. N. (1989). Contemplative prayer. Image Books.

Chicago Style (17th ed.) Citation

Merton, Thomas, and Thich Nhat Hanh. Contemplative Prayer. New York [etc.]: Image Books, 1989.

MLA (9th ed.) Citation

Merton, Thomas, and Thich Nhat Hanh. Contemplative Prayer. Image Books, 1989.

Warning: These citations may not always be 100% accurate.