TA Engineering (General). Civil engineering (General) 56 TP Chemical technology 41 HD28 Management. Industrial Management 35 TH Building construction 31 TJ Mechanical engineering and machinery 30 TK Electrical engineering. Electronics Nuclear engineering 29 QD Chemistry 26 QA75 Electronic computers. Computer science 20 K Law (General) 18 HD Industries. Land use. Labor 14 Q Science (General) 13 T Technology (General) 11 L Education (General) 10 NA Architecture 10 QC Physics 10 TD Environmental technology. Sanitary engineering 9 LB Theory and practice of education 6 QE Geology 6 QA Mathematics 5 HD1394-1394.5 Real estate management 4 HD30.2 Knowledge management 4 HD30.213 Management information systems. Decision support systems 4 HT Communities. Classes. Races 4 H Social Sciences (General) 3 QA76 Computer software 3 QH Natural history 3 R Medicine (General) 3 BP Islam. Bahaism. Theosophy, etc 2 G Geography (General) 2 G70.212-70.215 Geographic information system 2