Classification
620 - Engineering & allied operations
4,401
621 - Applied physics
3,185
531 - Classical mechanics; solid mechanics
1,134
600 - Technology
856
700 - The arts; fine & decorative arts
771
530 - Physics
762
629 - Other branches of engineering
657
333 - Economics of land & energy
635
900 - History & geography
505
000 - Computer science, information & general works
495
610 - Medicine & health
402
330 - Economics
305
363 - Other social problems & services
267
003 - Systems
258
624 - Civil engineering
255
500 - Natural sciences & mathematics
247
515 - Analysis
228
580 - Plants (Botany)
215
380 - Commerce, communications & transportation
200
670 - Manufacturing
200
519 - Probabilities & applied mathematics
183
540 - Chemistry & allied sciences
177
320 - Political science
159
576 - Genetics & evolution
157
690 - Buildings
149
140 - Specific philosophical schools
139
658 - General management
138
006 - Special computer methods
129
660 - Chemical engineering
126
340 - Law
108
414 - Phonology & phonetics
98
551 - Geology, hydrology & meteorology
98
541 - Physical chemistry
89
510 - Mathematics
86
630 - Agriculture & related technologies
77
384 - Communications; telecommunication
76
518 - Numerical analysis
74
536 - Heat
72
745 - Decorative arts
72
520 - Astronomy & allied sciences
67
720 - Architecture
62
547 - Organic chemistry
58
691 - Building materials
54
004 - Data processing & computer science
53
370 - Education
53
612 - Human physiology
49
304 - Factors affecting social behavior
48
534 - Sound & related vibrations
44
331 - Labor economics
41
615 - Pharmacology & therapeutics
40
more ...