TP Chemical technology 8 QA75 Electronic computers. Computer science 5 TK Electrical engineering. Electronics Nuclear engineering 3 HD28 Management. Industrial Management 2 L Education (General) 2 QH Natural history 2 T Technology (General) 2 TJ Mechanical engineering and machinery 2 TK5101-6720 Telecommunication 2 G154.9-155.8 Travel and state. Tourism 1 GE Environmental Sciences 1 H Social Sciences (General) 1 HD Industries. Land use. Labor 1 HD30.2 Knowledge management 1 LB1603 Secondary Education. High schools 1 P Philology. Linguistics 1 Q Science (General) 1 QA Mathematics 1 QC Physics 1 QD Chemistry 1 SB Plant culture 1 TA Engineering (General). Civil engineering (General) 1 TH Building construction 1