Jerome Clark Related books Encyclopedia of Strange and Unexplained Physical Phenomena Gale / Cengage Learning • 1993 Strange Sightings, Incredible Occurrences & Puzzling Physical Visible Ink Pr • 1999 The UFO Book: Encyclopedia of the Extraterrestrial Independent Pub Group • 1997 The UFO encyclopedia Omnigraphics Inc • 1998 Unexplained!: 347 Strange Sightings, Incredible Occurrences, and Puzzling Physical Phenomena Visible Ink Press • 1993