| title | media type | ISBN-13 | year of publication |
|---|---|---|---|
| Bringing Ufos Down to Earth | Paperback | 978-1-57392-148-0 | 1997 |
| Secret sentries in space, | Hardcover | 978-0-394-46972-0 | 1971 |
| The Real Roswell Crashed-Saucer Coverup | " | 978-1-57392-164-0 | 1997 |
| Ufo Abductions: A Dangerous Game | Paperback | 978-0-87975-509-6 | 1989 |
| Ufos Explained | " | 978-0-394-72106-4 | 1976 |
| Ufos Explained | Hardcover | 978-0-394-49215-5 | 1975 |
| Ufos--Identified | " | 978-0-394-45003-2 | 1968 |
| Ufos: The Public Deceived | Paperback | 978-0-87975-322-1 | 1986 |
J.K · P.J. · P.K. · Philip J. · Philip K. · Philip Klass