Case studies City planning 9 History 6 Comprehensive high schools 4 Local government 4 Regional planning 4 Cities and towns 3 Day care centers 3 School children 3 Study and teaching (Secondary) 3 Child psychology 2 Curricula 2 Education, Secondary 2 Employment 2 Family 2 Fraud in science 2 Labor and laboring classes 2 Old age assistance 2 Passenger traffic 2 Planning 2 Politics and government 2 Prisoners 2 Psychologists 2 Rehabilitation 2 Rural conditions 2 School management and organization 2 Social conditions 2 Social life and customs 2 Teachers 2 Transportation 2