Classification
333 - Economics of land & energy
211
621 - Applied physics
63
551 - Geology, hydrology & meteorology
60
577 - Ecology
39
550 - Earth sciences
38
628 - Sanitary & municipal engineering
35
363 - Other social problems & services
26
910 - Geography & travel
24
620 - Engineering & allied operations
17
570 - Life sciences; biology
14
572 - Biochemistry
14
624 - Civil engineering
10
304 - Factors affecting social behavior
7
519 - Probabilities & applied mathematics
5
571 - Physiology & related subjects
5
634 - Orchards, fruits & forestry
5
003 - Systems
4
320 - Political science
4
530 - Physics
4
630 - Agriculture & related technologies
4
660 - Chemical engineering
4
338 - Production
3
581 - Specific topics in natural history
3
590 - Animals (Zoology)
3
631 - Techniques, equipment & materials
3
690 - Buildings
3
006 - Special computer methods
2
300 - Social sciences
2
500 - Natural sciences & mathematics
2
515 - Analysis
2
541 - Physical chemistry
2
549 - Mineralogy
2
560 - Paleontology; paleozoology
2
579 - Microorganisms, fungi & algae
2
580 - Plants (Botany)
2
610 - Medicine & health
2
613 - Personal health & safety
2
614 - Incidence & prevention of disease
2
900 - History & geography
2
005 - Computer programming, programs & data
1
040 - [Unassigned]
1
142 - Critical philosophy
1
158 - Applied psychology
1
301 - Sociology & anthropology
1
303 - Social processes
1
330 - Economics
1
518 - Numerical analysis
1
520 - Astronomy & allied sciences
1
523 - Specific celestial bodies & phenomena
1
531 - Classical mechanics; solid mechanics
1
more ...