Unidentifiable Flying Objects, The Dwindling Probability of Solving the UFO Enigma, Schiffer Publishing, Ltd., Schiffer,UFOs and extraterrestrial beings,Unexplained phenomena / the paranormal, UFO; gray aliens, grey aliens; alien abduction; paranormal,, , United States, en-UShttps://schifferbooks.comUFO; gray aliens, grey aliens; alien abduction; paranormal, [BLURB],[CITY],,books, ebooks, biblet, Book2look