TA Engineering (General). Civil engineering (General) 89 T Technology (General) 68 TP Chemical technology 57 TH Building construction 32 TD Environmental technology. Sanitary engineering 31 QA75 Electronic computers. Computer science 27 TK Electrical engineering. Electronics Nuclear engineering 23 HD28 Management. Industrial Management 16 L Education (General) 16 TJ Mechanical engineering and machinery 14 LB Theory and practice of education 11 H Social Sciences (General) 7 QA76 Computer software 7 HD Industries. Land use. Labor 5 NA Architecture 5 Q Science (General) 5 QE Geology 5 T Technology 5 T58.5-58.64 Information technology 5 TH434-437 Quantity surveying 5 G Geography (General) 4 K Law (General) 4 HD30.213 Management information systems. Decision support systems 3 LB2300 Higher Education 3 G70.212-70.215 Geographic information system 2 GE Environmental Sciences 2 HF Commerce 2 HG Finance 2 QC Physics 2 R Medicine (General) 2