The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.The Secret of Shark Reef (1979) - Front cover of ''The Secret of Shark Reef''.The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Three Investigators - Front cover from the ''The Three Investigators'' series.The Mystery of the Headless Horse (1977) - Front cover of ''The Mystery of the Headless Horse''.The Mystery of the Flaming Footprints (1971) - Front cover of ''The Mystery of the Flaming Footprints''.The Mystery of the Death Trap Mine - Front cover of ''The Mystery of the Death Trap Mine''.The Mystery of the Death Trap Mine (1976) - Front cover of ''The Mystery of the Death Trap Mine''.The Mystery of the Vanishing Treasure (1966) - Front cover of ''The Mystery of the Vanishing Treasure''.The Mystery of the Singing Serpent (1972) - Front cover of ''The Mystery of the Singing Serpent''.The Secret of the Crooked Cat (1970) - Front cover of ''The Secret of the Crooked Cat''.The Mystery of the Deadly Double (1978) - Front cover of ''The Mystery of the Deadly Double''.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Mystery of the Whispering Mummy (1965) - Front cover of ''The Mystery of the Whispering Mummy''.The Mystery of the Dancing Devil (1976) - Front cover of ''The Mystery of the Dancing Devil''.