* *Helsingfors' (1952)
* *Resa i mörkret' (1955)
* *The Voyage of the Damned' (1971)
* *The Last Voyage of the Almirante' (1980)
* *The Devil's Marchioness' (1986)
Facklitteratur
* *Män of Valour' (1942)
* *Till land, i luften och till sjöss' (1946)
* *En hedersaffär:Moskva, juni 1612' (1948)
* *The Savage Years:a History of the First Five Years of the Third World War (1954)
* *White Cargo:The History of the White Slave Trade in Black Africa' (1968)
* *Dubbel, dubbel, slit och problem:en historia om den svarta magiska konsten från antiken till nutid' (1971)
* *The Rape of Christianity:the Dispatches of T. L. Constant:1840–1841' (1973)
* *Dracula:a Biography' (1973)
* *Bloody Murder:the Real Dracula's History and Adventures' (1976)
* *Hitler mot Ryssland:östfronten, 1941-1945' (1978)
* *The Last Secrets of Temple:Mystery of Rennes-le-Château and the Priory of Sion' (1981)
* *Prince Philip:the First Biography' (1991)
* *The White Road to the Temple:a Study in the Legends and Teachings of the Knights Templars' (1995)