The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Secret of Skeleton Island (1966) - Front cover of ''The Secret of Skeleton Island''.The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Secret of Skeleton Island (1966) - Front cover of ''The Secret of Skeleton Island''.The Mystery of the Coughing Dragon (1970) - Illustration for the Danish release of ''The Mystery of the Coughing Dragon'' by artist Peter Madsen.The Mystery of the Death Trap Mine (1976) - Front cover of ''The Mystery of the Death Trap Mine''.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Secret of the Haunted Mirror (1974) - Front cover of ''The Secret of the Haunted Mirror''.The Mystery of the Whispering Mummy (1965) - Front cover of ''The Mystery of the Whispering Mummy''.The Mystery of the Magic Circle (1978) - Front cover of ''The Mystery of the Magic Circle''.The Mystery of the Coughing Dragon (1970) - Front cover of ''The Mystery of the Coughing Dragon''.The Mystery of the Laughing Shadow (1969) - Front cover of ''The Mystery of the Laughing Shadow''.The Mystery of the Sinister Scarecrow (1979) - Front cover of ''The Mystery of the Sinister Scarecrow''.The Mystery of the Coughing Dragon (1970) - Illustration for ''The Mystery of the Coughing Dragon'' by artist Harry Kane.The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.