Science Technology 471 Philosophy 368 History 334 Study and teaching 323 Engineering 260 Mathematics 227 Data processing 197 Research 175 Social aspects 120 Study and teaching (Elementary) 97 Education 91 Methodology 90 Philosophy (General) 87 Physics 85 Engineering mathematics 74 Study and teaching (Secondary) 67 Statistical methods 65 Experiments 59 Mathematical models 58 Encyclopedias 57 Study and teaching (Higher) 54 Islam and science 53 Chemistry 48 Juvenile literature 47 Numerical analysis 44 Vocational guidance 37 Popular works 36 Medicine 34 Social sciences 34