Columbia subject headings:
Harvard subject headings:
Area 51 (Nev.)
Government information--United States
Human-alien encounters
Unidentified flying objects--Sightings and encounters
Unidentified flying objects--Sightings and encounters--New Mexico--Roswell
Princeton subject headings:
Government information--United States.
Human-alien encounters.
Unidentified flying objects--Sightings and encounters--New Mexico--Roswell.
Unidentified flying objects--Sightings and encounters.