Analysis 175 Enzymes 174 History 82 Mathematical models 51 Data processing 39 Mathematics 35 Addresses, essays, lectures 28 Psychology 27 Chemistry, Organic 24 Collected works 24 Politics and government 24 Research 24 Food 23 Methodology 23 Psychological aspects 23 History and criticism 22 Pollution 21 Polymers and polymerization 20 Synthesis 20 Cognition 19 Materials 19 Children 18 Economic conditions 18 Environmental aspects 18 Social aspects 18 Technique 18 Microbiology 17 Statistical methods 17 Perception 16 Physiological effect 15