TK Electrical engineering. Electronics Nuclear engineering 280 TJ Mechanical engineering and machinery 95 TA Engineering (General). Civil engineering (General) 46 QA75 Electronic computers. Computer science 30 T Technology (General) 29 TP Chemical technology 23 QA76 Computer software 12 Q Science (General) 11 TH Building construction 11 TL Motor vehicles. Aeronautics. Astronautics 11 QA Mathematics 9 NA Architecture 8 HE Transportation and Communications 7 HD28 Management. Industrial Management 6 QC Physics 6 Unspecified 6 H Social Sciences (General) 5 HD Industries. Land use. Labor 5 QD Chemistry 5 T58.5-58.64 Information technology 5 G70.212-70.215 Geographic information system 4 TK7885-7895 Computer engineer. Computer hardware 4 QH301 Biology 3 TK5101-6720 Telecommunication 3 TS Manufactures 3 G Geography (General) 2 GA Mathematical geography. Cartography 2 L Education (General) 2 LB Theory and practice of education 2 LB2300 Higher Education 2