Classification
005 - Computer programming, programs & data
51
006 - Special computer methods
29
616 - Diseases
28
004 - Data processing & computer science
23
519 - Probabilities & applied mathematics
14
620 - Engineering & allied operations
14
621 - Applied physics
14
617 - Surgery & related medical specialties
13
520 - Astronomy & allied sciences
12
512 - Algebra
11
003 - Systems
10
501 - Philosophy & theory
10
610 - Medicine & health
10
515 - Analysis
9
629 - Other branches of engineering
9
300 - Social sciences
8
001 - Knowledge
7
142 - Critical philosophy
7
330 - Economics
7
523 - Specific celestial bodies & phenomena
7
530 - Physics
7
571 - Physiology & related subjects
7
658 - General management
7
551 - Geology, hydrology & meteorology
6
572 - Biochemistry
6
615 - Pharmacology & therapeutics
6
363 - Other social problems & services
5
371 - Schools & their activities; special education
5
577 - Ecology
5
500 - Natural sciences & mathematics
4
541 - Physical chemistry
4
040 - [Unassigned]
3
510 - Mathematics
3
518 - Numerical analysis
3
531 - Classical mechanics; solid mechanics
3
534 - Sound & related vibrations
3
539 - Modern physics
3
547 - Organic chemistry
3
570 - Life sciences; biology
3
612 - Human physiology
3
613 - Personal health & safety
3
614 - Incidence & prevention of disease
3
628 - Sanitary & municipal engineering
3
660 - Chemical engineering
3
150 - Psychology
2
160 - Logic
2
190 - Modern western philosophy
2
304 - Factors affecting social behavior
2
306 - Culture & institutions
2
333 - Economics of land & energy
2
more ...