The Field Guide to Ghosts and Other Apparitions: A Classification of Various Unidentified Aerial Phenomena Based on Eyewitness Accounts | Hilary Evans, Patrick Huyghe
Describes encounters of people with various types of ghosts, and their experiences, including what they saw, heard, smelled, or felt.
The Field Guide to Ghosts and Other Apparitions: A Classification of Various Unidentified Aerial Phenomena Based on Eyewitness Accounts | 
