Addresses, essays, lectures 16 International economic relations 7 Study and teaching 7 Underdeveloped areas 7 Social aspects 6 History 5 Management 5 Congresses 4 Economic conditions 4 Education 4 Education, Higher 4 Education, Humanistic 4 Foreign relations 4 Science 4 Behavior therapy 3 Chemistry, Analytic 3 Commerce 3 Economic aspects 3 International cooperation 3 Operations research 3 Technology transfer 3 Aerospace and Aeronautics 2 Aggressiveness (Psychology) 2 American literature 2 Astronautics 2 Astronomy 2 Astrophysics 2 Biomedical engineering 2 COMPUTER ART 2 Chemical engineering 2