Dimensions: A Casebook of Alien Contact
The first part of a trilogy examined the history of UFO reports through a variety of times and places while arguing that the extraterrestrial theory is a coverup for something even stranger.
"Dimensions: A Casebook of Alien Contact," written by Dr. Jacques Vallée, was the first volume of his trilogy and was published in 1988. Vallée looked in the history leading up to the UFO phenomenon while examining reported alien abductions throughout different countries and times. Vallée looked into the coverups but also believed that theory of extraterrestrials was not nearly bizarre enough to account for the facts.