Book excerpt: Poltergeists was first published in 1979 and rapidly established itself as a leading work on the topic. It has been frequently referred to as groundbreaking and a classic of the genre. Illustrative cases from all over the world are presented, dating from the sixteenth century to the late twentieth. Included are destructive cases, fantastical cases, poltergeist assaults, phenomena that are allegedly brought about by a witch or a demon, and others which appear to be the handiwork of a deceased human being. Most cases are sourced from contemporary notes or diaries, often little known or unknown but nevertheless fascinating, with many translated from non-English language sources. The book includes a computer analysis of the leading characteristics of hundreds of cases of poltergeists and hauntings, and offers tentative conclusions as to the natural 'clusters' into which the cases fall. Poltergeists is essential reading for anyone who is interested in parapsychology and the paranormal.