TK Electrical engineering. Electronics Nuclear engineering 15 TA Engineering (General). Civil engineering (General) 13 QA75 Electronic computers. Computer science 7 QC Physics 5 TJ Mechanical engineering and machinery 5 HD1394-1394.5 Real estate management 4 HD28 Management. Industrial Management 4 TP Chemical technology 4 LB Theory and practice of education 3 HF Commerce 2 QE Geology 2 TC Hydraulic engineering. Ocean engineering 2 BP Islam. Bahaism. Theosophy, etc 1 G154.9-155.8 Travel and state. Tourism 1 G70.212-70.215 Geographic information system 1 GE Environmental Sciences 1 HE Transportation and Communications 1 L Education (General) 1 LB2300 Higher Education 1 NK Decorative arts Applied arts Decoration and ornament 1 QA Mathematics 1 QD Chemistry 1 S Agriculture (General) 1 T Technology (General) 1 T58.5-58.64 Information technology 1 TH434-437 Quantity surveying 1 TL Motor vehicles. Aeronautics. Astronautics 1 Unspecified 1 VM Naval architecture. Shipbuilding. Marine engineering 1 Z Bibliography. Library Science. Information Resources 1