TC Hydraulic engineering. Ocean engineering 46 TA Engineering (General). Civil engineering (General) 43 TJ Mechanical engineering and machinery 20 TP Chemical technology 16 TK Electrical engineering. Electronics Nuclear engineering 12 TD Environmental technology. Sanitary engineering 7 QA Mathematics 4 GE Environmental Sciences 2 HD Industries. Land use. Labor 2 TL Motor vehicles. Aeronautics. Astronautics 2 HE Transportation and Communications 1 LB Theory and practice of education 1 Q Science (General) 1 QA76 Computer software 1 QE Geology 1 SH Aquaculture. Fisheries. Angling 1 T58.5-58.64 Information technology 1