Congresses 333 Periodicals 72 Group theory 68 Study and teaching 58 Data processing 54 History 47 Politics and government 46 Research 46 Small groups 45 Group psychotherapy 43 Management 38 Minorities 38 Social conditions 37 Environmental aspects 36 Accounting 34 Design and construction 34 Education 34 Economic aspects 33 Social groups 33 Safety measures 32 Group relations training 31 Finance 30 Roads 29 Pressure groups 28 Representations of groups 28 Traffic safety 28 Bibliography 26 Mathematical models 26 Case studies 25 Handbooks, manuals, etc 24