UFOs Over New York: A True History of Extraterrestrial Encounters in the Empire State, Shiffer Publishing, 2008

UFOs Over Topanga Canyon: Eyewitness Accounts of the California Sightings, Llewellyn, 1999

UFOs: A Covert Agenda: The British Government’s UFO Top Secrets Exposed,Simon & Schuster, 1997

UFOs: Generals, Pilots and Government Officials Go On the Record, Crown, 2010

UFOs: The Secret History, Marlowe and Co., 1998

Ultimate UFO! The Complete Evidence (DVD)

Unconventional Flying Objects: A Scientific Analysis

Undersea UFO Base: An In-Depth Investigation of USOs in the Santa Catalina Channel, Blue Giant Books, 2018

Unearthly Disclosure: Conflicting Interests in the Control of Extraterrestrial Intelligence, Century/Random House, 2000

Unidentified: The UFO Phenomenon: How World Governments Have Conspired to Conceal Humanity’s Biggest Secret, New Page Books, 2014