TK Electrical engineering. Electronics Nuclear engineering 53 QA75 Electronic computers. Computer science 50 TJ Mechanical engineering and machinery 26 QA Mathematics 22 TP Chemical technology 22 TA Engineering (General). Civil engineering (General) 17 Q Science (General) 10 QA76 Computer software 7 T Technology (General) 6 L Education (General) 5 QC Physics 5 Unspecified 4 TC Hydraulic engineering. Ocean engineering 3 TK7885-7895 Computer engineer. Computer hardware 3 TL Motor vehicles. Aeronautics. Astronautics 2 TS Manufactures 2 G Geography (General) 1 GA Mathematical geography. Cartography 1 HD Industries. Land use. Labor 1 HE Transportation and Communications 1 HT101-395 Sociology, Urban 1 LB Theory and practice of education 1 NA Architecture 1 QD Chemistry 1 QH Natural history 1 T58.5-58.64 Information technology 1 TH434-437 Quantity surveying 1 TK5101-6720 Telecommunication 1 TR Photography 1 VM Naval architecture. Shipbuilding. Marine engineering 1