| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Project Identification: The First Scientific Field Study of Ufo Phenomena | 978-0-13-730705-0 (0-13-730705-5) | 1982 |
| Project Identification: The first scientific field study of UFO phenomena | 978-0-13-730713-5 (0-13-730713-6) | 1981 |