History 132 World War, 1939-1945 99 Campaigns 94 Biography 66 Politics and government 51 Work groups 37 Leadership 33 Juvenile literature 32 United States 25 Western Front 24 Foreign relations 23 Malay fiction 22 Teams in the workplace 22 Terrorism 20 Group relations training 18 Management 18 National security 18 Small groups 18 Thesis 18 Congresses 17 Handbooks, manuals, etc 17 Case studies 16 Regimental histories 16 Armed Forces 15 Drone aircraft 14 Employees 14 Generals 13 Military policy 13 Religious aspects 13 Training of 13