In 1955, Morris K. Jessup, an astronomer and former graduate-level researcher, published The Case for the UFO, a book about unidentified flying objects that contains some theories about the different means of propulsion that flying-saucer-style UFOs might use.

UFO researcher Ted Thoben has declared that the area of the town is one of two UFO windows in America, the other being the Michigan Rectangle.

He never voiced this claim prior to 1992, and it wasn't until 2006 that he decided the incident took place at Oscar Flight, having been persuaded to reach that conclusion by UFO researcher Robert Hastings.

It should be noted as well that it was only upon the instigation of UFO researcher Robert Hastings that Jamison and Salas finally agreed that the event they recalled took place at Oscar Flight on March 24, 1967.

In 1978, Canadian researcher Arthur Bray uncovered previously classified Canadian UFO documents naming Dr. Vannevar Bush as heading a highly secret UFO investigation group within the U. S. Research and Development Board.

In 1983, Doty also contacted UFO researcher and journalist Linda Moulton Howe, revealing alleged high-level UFO documents, including those describing crashed alien flying saucers and recovery of aliens.

In 1982 Moore approached nuclear physicist and UFO researcher Stanton T. Friedman about creating bogus Roswell documents, with the idea of encouraging witnesses to come forward.

* UFO researcher Jerome Clark discusses the MJ-12 documents in the " Hoaxes " section of his The UFO Book, and strongly favors a hoax interpretation.

This terminology and the system of classification behind it was started by astronomer and UFO researcher J. Allen Hynek, and was first suggested in his 1972 book The UFO Experience: A Scientific Inquiry.

The UFO researcher Ted Bloecher proposed six subtypes for the close encounters of the third kind in the Hynek's scale.

Scientific UFO research suffers from the fact that the phenomena under observation do not usually make predictable appearances at a time and place convenient for the researcher.

In the US, groups and affiliates interested in UFO investigation number in the hundreds, of which a few have achieved prominence based on their longevity, size, and researcher involvement with scientific credentials.

Other early contributors included writer and researcher Nigel Watson ( Chairman of the Scunthorpe UFO Research Society ' SUFORS '), who wrote " Mysterious Moon " for The News # 2.

UFO researcher Jerome Clark goes so far as to write that, by this time, Blue Book had " lost all credibility.

Physicist and UFO researcher Dr. James E. McDonald once flatly declared that Quintanilla was " not competent " from either a scientific or an investigative perspective.

However, researcher Brad Sparks, citing research from the May, 1970 issue of NICAP's UFO Investigator, reports that the last day of Blue Book activity was actually January 30, 1970.

* In 1996, British researcher Tony Dodd published a story about alien bodies supposedly taken to Porton Down from the site of an alleged UFO crash on the Berwyn Mountains in North Wales, an event most commonly referred to as the Berwyn Mountain Incident.

They were willing to discuss the UFO encounter with friends, family and the occasional UFO researcher, but the Hills apparently made no effort to seek publicity.

Commercial artist and UFO researcher Pete Navarro acquired the remaining books.

* The UFO Book: Encyclopedia of the Extraterrestrial, Jerome Clark, author.

* Jerome Clark, The UFO Book: Encyclopedia of the Extraterrestrial ; Visible Ink, 1998 ; ISBN 1-57859-029-9

* Jerome Clark, The UFO Book: Encyclopedia of the Extraterrestrial, Visible Ink, 1998, ISBN 1-57859-029-9

The U. S. Air Force formally listed the Arnold case as a mirage ; this is one of many explanations that have been disputed by critics, and researchers Jerome Clark, author of The UFO Book ( 1998 ) and Ronald Story, editor of The Encyclopedia of UFOs ( 1980 ).

* Clark, Jerome, The UFO Encyclopedia: The Phenomenon from the Beginning, Volume 2, A-K, Detroit: Omnigraphics, 1998 ( 2nd edition, 2005 ), ISBN 0-7808-0097-4

UFO historian Jerome Clark writes that " Few abduction reports have generated as much controversy " as the Walton case.

* Clark, Jerome, The UFO Book: Encyclopedia of the Extraterrestrial ( Visible Ink, 1998 ).

However, even before Wells, there was a sudden upsurge in reports in " Mystery airships " in the U. S. UFO historians Jerome Clark and David M. Jacobs note that extraterrestrial visitation, particularly from Mars, was sometimes proposed to explain these mystery airship waves.

* Clark, Jerome, The UFO Encyclopedia: The Phenomenon from the Beginning, Volume 1, A-K Detroit: Omnigraphics, 1998 ( 2nd edition, 2005 ), ISBN 0-7808-0097-4

* Clark, Jerome, The UFO Encyclopedia: The Phenomenon from the Beginning, Volume 2, L-Z Detroit: Omnigraphics, 1998 ( 2nd edition, 2005 ), ISBN 0-7808-0097-4

* Clark, Jerome, The UFO Book: Encyclopedia of the Extraterrestrial ; Visible Ink Press, 1998.

" ( Jacobs, 15 ) Some have suggested this was the earliest report of cattle mutilation ( In 1982, however, UFO researcher Jerome Clark debunked this story, and confirmed via interviews and Hamilton's own affidavit that the story was a successful attempt to win a Liar's Club competition to create the most outlandish tall tale ).

* Jerome Clark ; The UFO Book: Encyclopedia of the Extraterrestrial ; Visible Ink, 1998 ; ISBN 1-57859-029-9

* Jerome Clark, " The Extraterrestrial Hypothesis in the Early UFO Age " ( pp. 122 – 140 in UFOs and Abductions: Challenging the Borders of Knowledge, David M. Jacobs, editor ; University Press of Kansas, 2000 ; ISBN 0-7006-1032-4 )

* Clark, Jerome, The UFO Encyclopedia: The Phenomenon from the Beginning, Volume 1: A-K ( second edition ); Detroit: Omnigraphics, 1998 ; ISBN 0-7808-0097-4

Leading UFO researcher Jerome Clark argues that Vallée's first two UFO books were among the most scientifically sophisticated defenses of the ETH ever mounted.

* Interview: Jacques Vallée Discusses UFO Control System with Jerome Clark ( 1978 )

* Jerome Clark, The UFO Book: Encyclopedia of the Extraterrestrial, Visible Ink Press, 1998.

* Jerome Clark, The UFO Book: Encyclopedia of the Extraterrestrial ( Visible Ink, 1998 ), ISBN 1-57859-029-9

There he delivered a lecture, " Science in Default ", which Jerome Clark calls " one of the most powerful scientific defenses of UFO reality ever mounted ".

Similarly, Clark notes that Dr. Michael D. Swords has speculated that the Barker / Bender Men in Black case ( occurring shortly after the CIA-directed Robertson Panel issued its recommendations to spy on civilian UFO groups ) might have been a psychological warfare experiment.

Clark quotes from Gilson's official report: " These polygraph examinations prove that these five men did see some object they believed to be a UFO, and that Travis Walton was not injured or murdered by any of these men on that Wednesday ".

Clark quotes from McCarthy's official report: " Based on his reaction on all charts, it is the opinion of this examiner that Walton, in concert with others, is attempting to perpetrate a UFO hoax, and that he has not been on any spacecraft ".

Clark argues that Walton's account of his time on the UFO is quite different from the Hill account, and that furthermore, " there is not a great deal of similarity between Walton's and any other abduction narrative " publicly discussed as of November, 1975.

" ( Clark, 650 ) Especially inaccurate was the portion of the film detailing his time on the UFO ; it bears almost no resemblance to the original narrative.

By the early 1960s — after about a decade and a half of study — Clark writes that " Hynek's apparent turnaround on the UFO question was an open secret.