TA Engineering (General). Civil engineering (General) 43 QA75 Electronic computers. Computer science 18 G70.212-70.215 Geographic information system 13 TJ Mechanical engineering and machinery 11 HD28 Management. Industrial Management 8 TP Chemical technology 8 HD Industries. Land use. Labor 6 HD1394-1394.5 Real estate management 6 QA76 Computer software 6 TK Electrical engineering. Electronics Nuclear engineering 5 QE Geology 4 TH Building construction 4 QA Mathematics 3 QH Natural history 3 T Technology (General) 3 TK7885-7895 Computer engineer. Computer hardware 3 HE Transportation and Communications 2 HT101-395 Sociology, Urban 2 L Education (General) 2 NA Architecture 2 TD Environmental technology. Sanitary engineering 2 TH434-437 Quantity surveying 2 TS Manufactures 2 HD30.213 Management information systems. Decision support systems 1 HF Commerce 1 HT Communities. Classes. Races 1 LB Theory and practice of education 1 Q Science (General) 1 QH301 Biology 1 R Medicine (General) 1