TK Electrical engineering. Electronics Nuclear engineering 79 TJ Mechanical engineering and machinery 35 QA75 Electronic computers. Computer science 16 T Technology (General) 10 QA Mathematics 6 QA76 Computer software 5 T58.5-58.64 Information technology 3 TA Engineering (General). Civil engineering (General) 3 L Education (General) 2 Q Science 2 Q Science (General) 2 TC Hydraulic engineering. Ocean engineering 2 TL Motor vehicles. Aeronautics. Astronautics 2 GB Physical geography 1 LB Theory and practice of education 1 PN Literature (General) 1 QE Geology 1 QH301 Biology 1 RZ Other systems of medicine 1 S Agriculture (General) 1 T Technology 1 TG Bridge engineering 1 TH Building construction 1 TK5101-6720 Telecommunication 1 TS Manufactures 1 VM Naval architecture. Shipbuilding. Marine engineering 1