TA Engineering (General). Civil engineering (General) 26 TP Chemical technology 24 QD Chemistry 9 TJ Mechanical engineering and machinery 8 QA75 Electronic computers. Computer science 7 TK Electrical engineering. Electronics Nuclear engineering 6 QC Physics 5 Q Science (General) 4 QA76 Computer software 3 T Technology (General) 3 LB Theory and practice of education 2 QH301 Biology 2 R Medicine (General) 2 RD Surgery 2 TS Manufactures 2 BP Islam. Bahaism. Theosophy, etc 1 G70.39-70.6 Remote sensing 1 H Social Sciences (General) 1 L Education (General) 1 LB2300 Higher Education 1 NK Decorative arts Applied arts Decoration and ornament 1 QA Mathematics 1 RC0254 Neoplasms. Tumors. Oncology (including Cancer) 1 TC Hydraulic engineering. Ocean engineering 1 TD Environmental technology. Sanitary engineering 1 TK7885-7895 Computer engineer. Computer hardware 1 TL Motor vehicles. Aeronautics. Astronautics 1 Z Bibliography. Library Science. Information Resources 1