The Enneagram: Understanding Yourself and the Others in Your Life

The Spiritual Dimension of the Enneagram: Nine Faces of the Soul

The Pocket Enneagram: Understanding the 9 Types of People

The Sacred Enneagram: Finding Your Unique Path to Spiritual Growth

Principles of the Enneagram: What it is, how it works, and what it can do for you Second Edition, Edition 2

Discovering Your Personality Type: The Essential Introduction to the Enneagram

The Road Back to You: An Enneagram Journey to Self-Discovery

I Thought It Was Just Me (but it isn't): Making the Journey from "What Will People Think?" to "I Am Enough"

The Sociopath Next Door

The Enneagram of Passions and Virtues: Finding the Way Home

The Science of Getting Rich (The Unabridged Classic by Wallace D. Wattles)

Quiet: The Power of Introverts in a World That Can't Stop Talking

The Psychopath Inside: A Neuroscientist's Personal Journey into the Dark Side of the Brain

Enneagram Transformations: Releases and Affirmations for Healing Your Personality Type

The Enneagram Made Easy: Discover the 9 Types of People

The Powers of the Mind

The INFJ Revolution: Reclaim Your Power, Live Your Purpose, Heal the World

Surrounded by Idiots: The Four Types of Human Behavior and How to Effectively Communicate with Each in Business (and in Life)