| title | ISBN-13 | year of publication |
|---|---|---|
| A Living Dinosaur?: In Search of Mokele-Mbembe | 978-90-04-08543-5 | 1987 |
| Alla ricerca degli animali misteriosi. Introduzione alla criptozoologia | 978-88-08-06186-7 | 1986 |
| Monsters of Loch Ness | 978-0-8040-0704-7 | 1980 |
| Searching for Hidden Animals: An Inquiry into Zoological Mysteries | 978-0-385-14897-9 | 1980 |
| The Monsters Of Loch Ness. | 978-0-86007-381-9 | 1976 |
Mackal Roy P: · P.M. · R. M. · R. P. · Roy-P
Brill · Doubleday · Futura Publications · Swallow Press · Zanichelli