A koan is a story, dialogue, question, or statement, supplemented with commentaries. They are used in Zen practice to provoke doubt in the mind, and test a student's progress.
- The Book of Equanimity commentary by Gerry Shishin Wick
- Gateless Barrier (Mumonkan) commentary by Zenkei Shibayama
- The Gateless Barrier: (Mumonkan) commentary by Robert Aitken
- Gateless Gate commentary by Koun Yamada Roshi
- Blue Cliff Record translated by Thomas Cleary
- Secrets of the Blue Cliff Record commentary by Hakuin and Tenkei translated by T. Cleary
- The Record of Transmitting the Light translated by Francis H. Cook
- Transmission of Light translated by T. Cleary
- The Book of Householer Koans by Eve Myonen Marko and Wendy Egyoku Nakao
