| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| A God for Lions: World Religions Simplified | 978-1-4033-5453-2 (1-4033-5453-7) | 2003 |
| Murder in the Vatican: The Revolutionary Life of John Paul and The CIA, Opus Dei and the 1978 Murders | 978-1-4343-8722-6 (1-4343-8722-4) | 2008 |
| Murder in the Vatican: The Revolutionary Life of John Paul and The Vatican Murders of 1978 | 978-1-4259-5309-6 (1-4259-5309-3) | 2006 |