Vital Signs: A Complete Guide to the Crop Circle Mystery and Why It Is Not a Hoax by Andy Thomas

Andy Thomas examines crop circles in Vital Signs, an illustrated guide to their history and the theories surrounding them. Photographs accompany discussions of patterns, reported physical effects and the experiences of researchers and observers.

Thomas argues against a purely hoax-based explanation. That position is the author's interpretation, not proof that crop circles have supernatural or extraterrestrial origins. This book is for readers exploring unexplained-phenomena literature, rather than a source of settled scientific conclusions.