Congresses 191 Research 68 Economic policy 51 Education 50 Study and teaching 47 Economic conditions 46 Environmental aspects 33 Management 30 Training of 29 Economic aspects 28 Economic development 28 Case studies 26 Planning 26 Computer programming 23 Data processing 23 Evaluation 23 History 23 Directories 22 Labor supply 22 Technology 21 Social aspects 20 Social policy 20 Administration 19 Agriculture 19 Universities and colleges 19 Employment 18 International business enterprises 18 Politics and government 18 Social conditions 18 Technological innovations 18