QA75 Electronic computers. Computer science 70 QA76 Computer software 44 TK Electrical engineering. Electronics Nuclear engineering 41 TA Engineering (General). Civil engineering (General) 30 QA Mathematics 18 TJ Mechanical engineering and machinery 17 QC Physics 11 Q Science (General) 10 TP Chemical technology 9 L Education (General) 7 TK7885-7895 Computer engineer. Computer hardware 5 HD28 Management. Industrial Management 4 HE Transportation and Communications 4 LB Theory and practice of education 4 TH Building construction 4 VM Naval architecture. Shipbuilding. Marine engineering 4 TD Environmental technology. Sanitary engineering 3 TS Manufactures 3 HD Industries. Land use. Labor 2 QD Chemistry 2 T Technology (General) 2 Unspecified 2 ZA4050 Electronic information resources 2 G70.212-70.215 Geographic information system 1 H Social Sciences (General) 1 HJ Public Finance 1 LB2361 Curriculum 1 LC Special aspects of education 1 TC Hydraulic engineering. Ocean engineering 1 TK5101-6720 Telecommunication 1