Caelum Incognitum — The interactive encyclopedia of ufology
Sighting databases
Techniques & investigation methods
NUFORC, MUFON, GEIPAN, Blue Book and others collect reports of very different kinds: free-form submissions, field investigations or military records. They lend themselves to statistics on the distribution of sightings, but their biases (media, population, season, fashion) forbid reading actual activity directly from them.