Equipment and supplies World War, 1939-1945 39 History 31 Armed Forces 10 Equipment 10 Design and construction 9 Firearms 7 Maintenance and repair 7 Military weapons 7 Airplanes, Military 6 Fighter planes 6 Periodicals 6 Special forces (Military science) 6 Weapons systems 6 Police 5 Uniforms 5 Air power 4 Fire extinction 4 Infantry 4 Microcomputers 4 Pictorial works 4 Sound 4 Special weapons and tactics units 4 Upgrading 4 Dissertations, Academic 3 History, Military 3 Pistols 3 Prevention 3 Telecommunication 3 Terrorism 3