TJ Mechanical engineering and machinery 50 TP Chemical technology 41 BP Islam. Bahaism. Theosophy, etc 37 TK Electrical engineering. Electronics Nuclear engineering 37 TA Engineering (General). Civil engineering (General) 32 QC Physics 30 QD Chemistry 29 QA75 Electronic computers. Computer science 20 HD28 Management. Industrial Management 14 Q Science (General) 14 T Technology (General) 11 QA Mathematics 9 LB Theory and practice of education 6 L Education (General) 5 QH Natural history 5 TS Manufactures 5 G70.212-70.215 Geographic information system 4 TH Building construction 4 Unspecified 4 HD Industries. Land use. Labor 3 HD1394-1394.5 Real estate management 3 QA76 Computer software 3 R Medicine (General) 3 TD Environmental technology. Sanitary engineering 3 G Geography (General) 2 HE Transportation and Communications 2 HF Commerce 2 HT101-395 Sociology, Urban 2 NA Architecture 2 TC Hydraulic engineering. Ocean engineering 2