QA75 Electronic computers. Computer science 46 TK Electrical engineering. Electronics Nuclear engineering 30 TA Engineering (General). Civil engineering (General) 27 QA Mathematics 21 NA Architecture 19 TJ Mechanical engineering and machinery 17 L Education (General) 15 Photography 14 Painting 13 Installation 11 QA76 Computer software 11 Visual education 10 Illustration 9 T Technology (General) 9 TH Building construction 9 H Social Sciences (General) 8 TP Chemical technology 8 Design 7 N Visual arts (General) 7 Performance 7 Study and teaching. Research 7 G Geography (General) 6 Graphic design 6 HD Industries. Land use. Labor 6 LB Theory and practice of education 6 Narrative 6 New Zealand 6 Fashion 5 G70.212-70.215 Geographic information system 5 General works 5