The Mystery of the Vanishing Treasure (1966) - Front cover of ''The Mystery of the Vanishing Treasure''.Alfred Hitchcock: The Three Investigators - Front cover from the ''The Three Investigators'' series.The Mystery of the Coughing Dragon (1970) - Illustration from ''The Mystery of the Coughing Dragon'' by artist Harry Kane.The Mystery of the Coughing Dragon (1970) - Illustration for ''The Mystery of the Coughing Dragon'' by artist Harry Kane.The Secret of Skeleton Island (1966) - Front cover of ''The Secret of Skeleton Island''.The Secret of the Phantom Lake (1973) - Front cover of ''The Secret of the Phantom Lake''.The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Mystery of the Dancing Devil (1976) - Front cover of ''The Mystery of the Dancing Devil''.The Secret of Shark Reef (1979) - Front cover of ''The Secret of Shark Reef''.The Mystery of the Screaming Clock (1968) - Front cover of ''The Mystery of the Screaming Clock''.The Secret of the Haunted Mirror (1974) - Front cover of ''The Secret of the Haunted Mirror''.The Mystery of the Dead Man's Riddle (1974) - Front cover of ''The Mystery of the Dead Man's Riddle''The Mystery of the Moaning Cave (1968) - Front cover of ''The Mystery of the Moaning Cave''.The Mystery of the Silver Spider (1967) - Front cover of ''The Mystery of the Silver Spider''.The Mystery of the Coughing Dragon (1970) - Front cover of ''The Mystery of the Coughing Dragon''.