The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.The Mystery of the Green Ghost (1965) - Front cover of ''The Mystery of the Green Ghost''.The Mystery of the Whispering Mummy (1965) - Front cover of ''The Mystery of the Whispering Mummy''.The Mystery of the Monster Mountain (1973) - Front cover of ''The Mystery of the Monster Mountain''.Alfred Hitchcock: The Three Investigators - Front cover from the ''The Three Investigators'' series.The Mystery of the Flaming Footprints (1971) - Front cover of ''The Mystery of the Flaming Footprints''.The Mystery of the Coughing Dragon (1970) - Front cover of ''The Mystery of the Coughing Dragon''.The Mystery of the Death Trap Mine - Front cover of ''The Mystery of the Death Trap Mine''.The Three Investigators - Front cover from the ''The Three Investigators'' series.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Mystery of the Moaning Cave (1968) - Front cover of ''The Mystery of the Moaning Cave''.The Mystery of the Death Trap Mine (1976) - Front cover of ''The Mystery of the Death Trap Mine''.The Mystery of the Coughing Dragon (1970) - Illustration from ''The Mystery of the Coughing Dragon'' by artist Harry Kane.The Mystery of the Singing Serpent (1972) - Front cover of ''The Mystery of the Singing Serpent''.The Mystery of the Deadly Double (1978) - Front cover of ''The Mystery of the Deadly Double''.