World War, 1939-1945 430 History 261 Aerial operations 155 Naval operations 124 Campaigns 93 Aerial operations, American 84 Operations research 80 Aerial operations, British 67 Operating systems (Computers) 67 Biography 61 Naval operations, American 53 Submarine 48 Armed Forces 43 World War, 1914-1918 40 World war, 1939-1945 39 Airplanes, Military 34 Commando operations 34 Special operations (Military science) 31 Naval operations, British 30 Operational readiness 30 Personal narratives, American 29 World War 28 United States 25 Fighter pilots 23 Naval operations, German 20 Vietnam War, 1961-1975 20 Microsoft Windows (Computer file) 19 Thesis 19 Special forces (Military science) 18 Air power 17