Air Progress Magazine / April 1968 / No Label / Sweden's Double Delta Fighter

Air Progress Magazine / May 1968 / No Label / North Korea's Air Force

Feb 1968 issue of Air Progress Aviation Magazine HRV-1 Hydrofoil

Air Progress Magazine / November 1968 / No Label / Inside Story Of Hump Flyers

Air Progress Magazine / October 1968 / No Label / Man Who Taught Red Baron

Air Progress Magazine / March 1968 / No Label / Ottumwa Fly-In For Antique Plane

Air Progress Magazine / September 1968 / No Label / When The Hawk Lost A Wing

Air Progress Magazine / June 1974 / No Label / New Pilot's Handbook