APA (7th ed.) Citation

Daniels, D. N., & Price, V. A. (2009). The essential enneagram: The definitive personality test and self-discovery guide (Revised and updated.). HarperOne.

Chicago Style (17th ed.) Citation

Daniels, David N., and Virginia Ann Price. The Essential Enneagram: The Definitive Personality Test and Self-discovery Guide. Revised and updated. New York: HarperOne, 2009.

MLA (8th ed.) Citation

Daniels, David N., and Virginia Ann Price. The Essential Enneagram: The Definitive Personality Test and Self-discovery Guide. Revised and updated. HarperOne, 2009.

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