The UFO Experience by J. Allen Hynek. Henry Regnery Company. (1972). Signed by Hynek on the first blank page. I have not authenticated the signature, but here is a picture of one that was authenticated online. First printing with no listing of subsequent printings. 6 1/4" x 9 1/4"  xii, 276 pages Hardcover with dust jacket. DUST JACKET: Heavy edge wear. Chipping to the top of the spine. Is price-clipped. BOOK: Light cover edge wear. Some bumping to cover tips. There is an old bookstore pencil price on the first blank page. Book Is heavily underlined in ink throughout. Previous owner signed in ink on the half title page. I cannot make out the previous owner's name in order to figure if it or the underlining is significant. Otherwise, no tears, folds or creases to pages. Binding is tight with no looseness to pages. Not ex-library, not remaindered and not a facsimile reprint. For sale by Jon Wobber, bookseller since 1978. JJ27a

"Josef Allen Hynek (May 1, 1910 – April 27, 1986) was an American astronomer, professor, and ufologist.[1] He is perhaps best remembered for his UFO research. Hynek acted as scientific advisor to UFO studies undertaken by the U.S. Air Force under three projects: Project Sign (1947–1949), Project Grudge (1949–1951) and Project Blue Book (1952–1969).

In later years, he conducted his own independent UFO research, developing the "Close Encounter" classification system. He was among the first people to conduct scientific analysis of reports and especially of trace evidence purportedly left by UFOs." -  Wikipedia