U.S. Government Journal UFO Article:

“OPERATIONS & TRAINING; UFO'S SERIOUS BUSINESS”

The Inspector General (TIG) Brief, Number 26,

Volume XI, 24 December 1959

(U.S. Air Force, Washington, D.C.)

Source: NICAP.org

The Inspector General Brief reports on Air Force Regulation 
200-2 (AFR 200-2):

http://www.nicap.org/directives/UFOS-SeriousBusiness.pdf

(U.S. Air Force/NICAP.org image)