The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Mystery of the Moaning Cave (1968) - Front cover of ''The Mystery of the Moaning Cave''.The Mystery of the Monster Mountain (1973) - Front cover of ''The Mystery of the Monster Mountain''.The Mystery of the Dancing Devil (1976) - Front cover of ''The Mystery of the Dancing Devil''.The Secret of Terror Castle (1964) - Front cover of ''The Secret of Terror Castle''.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Three Investigators - Front cover from the ''The Three Investigators'' series.The Secret of the Haunted Mirror (1974) - Front cover of ''The Secret of the Haunted Mirror''.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) - Front cover of ''The Mystery of the Coughing Dragon''.The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.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 Whispering Mummy (1965) - Front cover of ''The Mystery of the Whispering Mummy''.The Secret of the Phantom Lake (1973) - Front cover of ''The Secret of the Phantom Lake''.