U.S. Government UFO Document:
“UFO Fact Sheet”
(United States Department of Defense, Washington, D.C.)
This document presents the findings of the U.S. Air Force’s three UFO projects (Project Sign, Project Grudge and Project Blue Book):
http://www.dod.mil/pubs/foi/homeland_defense/UFOs/2d_af_1.pdf
The Seal of the United States Department of Defense (wikimedia.org) (wikimedia.org image)