Since I’m a big UFO nut, I’ve read a ton of books on the subject over the years. A while back I published a post on Reddit where I put together a list of UFO books and papers that, in my opinion, are worth reading if you really want to dig into the topic. So I figured I’d drop the list here too, in case anyone in this thread is interested in having a pretty extensive bibliography to check out.

The Flying Saucers Are Real by Donald Keyhoe
Flying Saucers From Outer Space by Donald Keyhoe
Flying Saucers - Top Secret by Donald Keyhoe
The Report on Unidentified Flying Objects by Edward Ruppelt
The UFO Evidence by Richard Hall
Report on the UFO Wave of 1952 by Richard Hall
Report on the UFO Wave of 1947 by Ted Bloecher
The UFO Experience: A Scientific Inquiry by J. Allen Hynek
The Hynek UFO Report: The Authoritative Account of the Project Blue Book Cover-Up by J. Allen Hynek
Project Blue Book Exposed by Kevin Randle
The Best of Project Blue Book by Kevin Randle
Invasion Washington: UFOs Over the Capitol by Kevin Randle
Scientific UFOlogy: How Scientific Methodology Can Prove the Reality of UFOs by Kevin Randle
Science in Default: Twenty-Two Years of Inadequate UFO Investigations by James McDonald
UFOs: An International Scientific Problem by James McDonald
Statement on Unidentified Flying Objects by James McDonald
UFOs? Yes! Where the Condon Committee Went Wrong by David Saunders
The UFO Enigma: A New Review of the Physical Evidence by Peter Sturrock
Unconventional Flying Objects: A Scientific Analysis by Paul Hill
UFOs: Generals, Pilots, and Government Officials Go on the Record by Leslie Kean
UFOs and Nukes: Extraordinary Encounters at Nuclear Weapons Sites by Robert Hastings
Earth Lights: Towards an Understanding of the Unidentified Flying Objects Enigma by Paul Devereux
Crash at Corona: The Definitive Study of the Roswell Incident by Stanton Friedman and Don Berliner
UFO Crash at Roswell by Kevin Randle and Donald Schmitt
The Truth About the UFO Crash at Roswell by Kevin Randle and Donald Schmitt
Roswell UFO Crash Update: Exposing the Military Cover-Up of the Century by Kevin Randle
Roswell in the 21st Century: The Evidence as it Exists Today by Kevin Randle
Roswell: Inconvenient Facts and the Will to Believe by Karl Pflock
Body Snatchers in the Desert: The Horrible Truth at the Heart of the Roswell Story by Nick Redfern
The Roswell UFO Conspiracy: Exposing A Shocking And Sinister Secret by Nick Redfern
Crashed Saucers: Evidence in Search for Proof by William Moore
UFO Crash Retrievals: The Complete Investigation – Status Reports I-VII by Leonard Stringfield
Crash — When UFOs Fall From the Sky by Kevin Randle
The Priests of High Strangeness: Co-Creation of the “Alien Abduction Phenomenon” by Carol Rainey
The Abduction Enigma: An Investigation of the Alien Abduction Phenomenon by Kevin Randle, Russ Estes, and William Cone
The Controllers: A New Hypothesis of Alien Abductions by Martin Cannon
The Space-Gods Revealed: A Close Look At The Theories Of Erich Von Daniken by Ronald Story
The Past Is Human: Debunking Von Daniken’s Gee-whiz Theories by Peter White
Ancient Atom Bombs: Fact, Fraud, and the Myth of Prehistoric Nuclear Warfare by Jason Colavito
Solving the 1897 Airship Mystery by Michael Busby
Project Beta: The Story of Paul Bennewitz, National Security, and the Creation of a Modern UFO Myth by Greg Bishop
Saucers, Spooks and Kooks: Disinformation in the Age of Aquarius by Adam Gorightly
X Descending: Two Extraordinary Films Reveal Lies, Deception, and Truth About Unidentified Flying Objects by Christian Lambright
Top Secret/Majic: Operation Majestic-12 and the United States Government’s UFO Cover-Up by Stanton Friedman and Don Berliner
Case MJ-12: The True Story Behind the Government’s UFO Conspiracies by Kevin Randle
The Secret Pratt Tapes and the Origins of MJ-12 by Brad Sparks and Barry Greenwood

Hope this helps anyone looking for good reads on the topic.