| title | ISBN-13 | year of publica- tion | other author(s) |
|---|---|---|---|
| Extraterrestrials: Investigations into the Unexplained | 978-0-7641-0907-2 | 1999 | Ivor Baddiel |
| Fantastic Creatures: Investigations into the Unexplained | 978-0-7641-1153-2 | 1999 | " |
| The Future: Investigations into the Unknown | 978-0-7641-1155-6 | 1999 | " |
| The Supernatural: Investigations into the Unexplained | 978-0-7641-0906-5 | 1999 | " |