| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Stanford Enneagram Discovery Inventory and Guide | 978-0-9666601-0-4 (0-9666601-0-2) | 1997 | David N. Daniels |
| The Essential Enneagram: The Definitive Personality Test and Self-Discovery Guide | 978-0-06-251676-3 (0-06-251676-0) | 2000 | " |
| Type a Behavior Pattern: A Model for Research and Practice | 978-0-12-564680-2 (0-12-564680-1) | 1982 | |
A. P. · A. Price · V. A. · V.P. · Virginia A. · Virginia Price
Academic Press · HarperCollins · Mind Garden, Inc.