Nonfiction
* *Adventures of a Psychic Detective* (1971)
* *Adventures in Psychical Research* (1975)
* *The Mystery of Psychic Healing* (1977)
* *The Psi Factor: A Look at the Evidence for Psychic Phenomena* (1978)
* *The Loch Ness Monster: The Evidence* (1979)
* *The Mystery of the Bermuda Triangle* (1979)
* *The Poltergeist Phenomenon* (1979)
* *The Search for Atlantis* (1979)
* *The UFO Mystery: A Look at the Evidence* (1981)
* *The World's Greatest UFO Mysteries* (1981)
* *The Book of Psychic Phenomena* (1982)
* *The Handbook of Psychic Phenomena* (1983)
* *The Encyclopedia of Psychic Phenomena* (1984)
Fiction
* *The Darkening of the Sun* (1957)
* *The Burning Glass* (1958)
* *The Devil's Tide* (1959)
* *The Black Death* (1960)
* *The Great Plague* (1961)
* *The Last Days of Sodom and Gomorrah* (1962)
* *The Ark of the Covenant* (1963)
* *The Curse of Tutankhamun* (1964)
* *The Secret of Atlantis* (1965)
* *The Day the Earth Stood Still* (1966)
* *The War of the Worlds* (1967)
* *The Time Machine* (1968)
* *20,000 Leagues Under the Sea* (1969)
* *Journey to the Center of the Earth* (1970)
* *The Return of Sherlock Holmes* (1971)
* *The Hound of the Baskervilles* (1972)
* *The Valley of Fear* (1973)
* *The Sign of the Four* (1974)
* *The Scarlet Thread* (1975)
* *The Last Adventure of Sherlock Holmes* (1976)
Poetry
* *To the Unknown* (1960)
* *The Voice of the Sea* (1962)
* *The Songs of the Stars* (1964)
* *The Echoes of Eternity* (1966)
* *The Whispers of the Wind* (1970)
* *The Music of the Spheres* (1972)