TK Electrical engineering. Electronics Nuclear engineering 33 TA Engineering (General). Civil engineering (General) 28 TJ Mechanical engineering and machinery 24 QA75 Electronic computers. Computer science 14 L Education (General) 13 TP Chemical technology 13 T Technology (General) 12 HD28 Management. Industrial Management 10 QA Mathematics 9 Q Science (General) 7 HF Commerce 6 H Social Sciences (General) 5 BP Islam. Bahaism. Theosophy, etc 4 HG Finance 4 QA76 Computer software 4 QC Physics 4 HB Economic Theory 3 HF5601 Accounting 3 QD Chemistry 3 HD1394-1394.5 Real estate management 2 TH Building construction 2 TH434-437 Quantity surveying 2 VM Naval architecture. Shipbuilding. Marine engineering 2 A General Works 1 BF Psychology 1 DS Asia 1 G Geography (General) 1 G70.212-70.215 Geographic information system 1 G70.39-70.6 Remote sensing 1 GA Mathematical geography. Cartography 1