TK Electrical engineering. Electronics Nuclear engineering 321 TP Chemical technology 303 TA Engineering (General). Civil engineering (General) 278 QA75 Electronic computers. Computer science 236 TJ Mechanical engineering and machinery 201 QA Mathematics 138 Q Science (General) 121 T Technology (General) 92 QD Chemistry 90 QC Physics 80 L Education (General) 59 HD28 Management. Industrial Management 56 QA76 Computer software 50 BP Islam. Bahaism. Theosophy, etc 42 HD1394-1394.5 Real estate management 36 TH Building construction 32 LB2300 Higher Education 31 H Social Sciences (General) 30 TD Environmental technology. Sanitary engineering 23 Q Science 18 LC Special aspects of education 17 TH434-437 Quantity surveying 16 LB Theory and practice of education 14 LB1603 Secondary Education. High schools 14 NA Architecture 14 R Medicine (General) 14 HT101-395 Sociology, Urban 13 QH301 Biology 12 TN Mining engineering. Metallurgy 12 TC Hydraulic engineering. Ocean engineering 11