1953 D. E. Keyhoe in Air Line Pilot Oct. 9/3 The UFO was estimated to be between 12,000 and 20,000 feet above the jets.

1956 E. J. Ruppelt Rep. Unidentified Flying Objects 13 UFO is the official term that I created to replace the words ‘flying saucers’.

1957 Flying Saucer Rev. III. vi. 9/2 Andrew Vaccari, of London Road, Neath, saw a crescent-shaped U.F.O. travelling at a terrific speed from the direction of Wern Mountain, Port Talbot, towards Mumbles.

1959 ‘J. Wyndham’ & L. Parkes Outward Urge ii. 86 Radar Watch here, sir..Two ufos observed approaching south-east by south.

1966 New Statesman 8 July 58/2 Flying saucers or Ufos..continue. They are now seen in all parts of the world and in increasing numbers.

1977 New Yorker 27 June 51/2 She talked to people who had seen strange sights—UFOs or sea monsters.

1983 Out of Town July 14/2 A relative of the marquess, celebrated for her obsession with flying saucers, scans the skies and..UFOs obligingly hover overhead.

1973 G. S. Hawkins Beyond Stonehenge vii. 117 We found no extraterrestrial artifacts. Nothing the least bit UFO-ish.

1978 J. Updike Coup (1979) iv. 130 Steely, spherical UFOish IBM type elements.

1992 alt.sewing 30 Dec. (Usenet newsgroup, accessed 21 Aug. 2018) I could quickly see what I had, throw out the impossible UFO's.., organize my non-quilt projects, and free up a little space.

2006 S. Pearl-McPhee Knitting Rules! 218 A UFO is seldom found alone, but instead roams the knitter's home in packs.

2019 @Tiny_Tigress 30 June in twitter.com (accessed 30 June 2019) Ok, I'm officially busting my butt to get as many UFOs finished as I can before July 26. I'm totally joining this crochet-a-long.