TK Electrical engineering. Electronics Nuclear engineering 16 QA75 Electronic computers. Computer science 12 L Education (General) 4 QA76 Computer software 3 TK7885-7895 Computer engineer. Computer hardware 2 TR Photography 2 HD Industries. Land use. Labor 1 HD28 Management. Industrial Management 1 HE Transportation and Communications 1 LB Theory and practice of education 1 LB2300 Higher Education 1 LC Special aspects of education 1 PE English 1 QC Physics 1 QH Natural history 1 R Medicine (General) 1 T Technology (General) 1 TA Engineering (General). Civil engineering (General) 1 TC Hydraulic engineering. Ocean engineering 1 TJ Mechanical engineering and machinery 1