In 1953 a retired United States Marine Corps Major wrote several books about his investigations into the UFO phenomenon. Major Donald E.Keyhoe was a respected officer and investigator. The back jacket of his book Flying Saucers from outer space published by Henry Holt and Company, New York has the following admission from the United States Air Force that the only reasonable explanation for the UFO's was the Alien explanation. As a past owner of the book and lost it, I found someone who also had a copy kept in the family, it was a pleasure and informative re-read. The A.F. Letter.