History 30 Leadership 14 Congresses 13 Management 13 Foreign relations 11 English language 10 Politics and government 9 Handbooks, manuals, etc 8 Economic conditions 6 Comparative law 5 Economic aspects 5 Economic policy 5 International relations 5 Judicial power 5 Problems, exercises, etc 5 Supervision of employees 5 United States 5 Armed Forces 4 Bibliography 4 Chinese 4 Employees 4 Executive ability 4 Libraries 4 National security 4 Personnel management 4 Pictorial works 4 Psychological aspects 4 Social conditions 4 Terrorism 4 Training of 4