| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| The Formula: Who Gets Sick, Who Gets Well, Who Is Happy, Who Is Unhappy, and Why | 978-1-887472-65-4 (1-887472-65-7) | 1999 |
| The Formula: Who Gets Sick, Who Gets Well, Who is Happy, Who is Unhappy and Why | 978-1-887472-10-4 (1-887472-10-X) | 1996 |