The Wisdom of the Enneagram: The Complete Guide to Psychological and Spiritual Growth for the Nine Personality Types The definitive book to date and a must have in one's collection.
The Enneagram: Understanding Yourself and the Others In Your Life Palmer uses the oral tradition in keeping with the Enneagram.
Please Understand Me: Character and Temperament Types A classic in understanding temperament and Jung.
The 4 Dimensional Manager: DiSC Strategies for Managing Different People in the Best Ways (Inscape Guide)
Follow Your True Colors to the Work You Love
Emotional Intelligence: 10th Anniversary Edition; Why It Can Matter More Than IQ
The 9 Ways of Working: How to Use the Enneagram to Discover Your Natural Strengths and Work More Effectively