Unidentified flying objects — Audiobooks
The Flying Saucers are Real
by Donald E. (Donald Edward) Keyhoe
The World of Flying Saucers: A Scientific Examination of a Major Myth of the Space Age
by Donald H. (Donald Howard) Menzel, Lyle Gifford Boyd
The Report on Unidentified Flying Objects
by Edward J. Ruppelt
Federal Bureau of Investigation FOIA Documents - Unidentified Flying Objects
by United States. Federal Bureau of Investigation
New lands
by Charles Fort