Assertion: blue book | /r/CapableOf | investigate ufo sightings
Facets:
value: for almost 20 years
type: TEMPORAL
Source sentences:
text: For almost 20 years, Blue Book investigated UFO sightings and reports, but in 1968, the infamous Condon Report , which was a product of the Air Force and the University of Colorado, took the final position that all UFO incidents were human delusion, hoaxes, or had some prosaic explanations.