L Education (General) 21 TP Chemical technology 9 LB Theory and practice of education 5 PE English 4 Q Science (General) 3 TA Engineering (General). Civil engineering (General) 3 HD28 Management. Industrial Management 2 QH Natural history 2 R Medicine (General) 2 BF Psychology 1 BP Islam. Bahaism. Theosophy, etc 1 H Social Sciences (General) 1 HD Industries. Land use. Labor 1 HD30.2 Knowledge management 1 HE Transportation and Communications 1 HT101-395 Sociology, Urban 1 L Education 1 LB1603 Secondary Education. High schools 1 LB2300 Higher Education 1 NA Architecture 1 PL Languages and literatures of Eastern Asia, Africa, Oceania 1 Q Science 1 QD Chemistry 1 TH Building construction 1 TJ Mechanical engineering and machinery 1