Columbia subject headings:
Aeronautics, Military--United States--History.
Air power--History.
Bombing, Aerial--United States--History.
Harvard subject headings:
Aeronautics, Military--United States--History
Air power--History.
Bombing, Aerial--United States--History.
Princeton subject headings:
Aeronautics, Military--United States--History.
Air power--History.
Bombing, Aerial--United States--History.