Columbia subject headings:
Harvard subject headings:
Radar in aeronautics--History.
Radar--Military applications--United States--History.
United States. Army. Air Corps--History.
United States. Army. Signal Corps--History.
Princeton subject headings:
Radar in aeronautics--History.
Radar--Military applications--United States--History.
United States. Army. Air Corps--History.
United States. Army. Signal Corps--History.