| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Letters from Prison: Felons Write about the Struggle for Life and Sanity Behind Bars | 978-0-00-200086-4 (0-00-200086-5) | 2002 |
| The Intimate Ape: Orangutans and the Secret Life of a Vanishing Species | 978-0-8065-3133-5 (0-8065-3133-9) | 2010 |