Education 136 Congresses 90 Study and teaching 55 Research 39 Educational planning 36 Science 28 Periodicals 23 Bibliography 21 Continuing education 21 Adult education 20 Arid regions 18 Information services 18 Literacy 18 Oceanography 18 Teachers 18 Training of 18 Economic aspects 17 Statistics 17 Directories 15 Economic development 14 Social sciences 14 Technology 14 Education, Higher 13 Hydrology 13 School buildings 13 Social aspects 12 Universities and colleges 12 Economic conditions 11 Education, Primary 11 Finance 11