Bob Held · Bob Holliday · Bob Holt · Bobby Holliday
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Return of the Mexican Gray Wolf: Back to the Blue | 978-0-8165-2295-8 (0-8165-2295-2) | 2003 |
| The Return of the Mexican Gray Wolf: Back to the Blue | 978-0-8165-2296-5 (0-8165-2296-0) | 2003 |