Classification
620 - Engineering & allied operations
74
540 - Chemistry & allied sciences
63
550 - Earth sciences
47
519 - Probabilities & applied mathematics
44
541 - Physical chemistry
41
530 - Physics
31
621 - Applied physics
27
551 - Geology, hydrology & meteorology
18
660 - Chemical engineering
18
600 - Technology
16
547 - Organic chemistry
15
570 - Life sciences; biology
14
610 - Medicine & health
13
306 - Culture & institutions
11
500 - Natural sciences & mathematics
10
577 - Ecology
10
612 - Human physiology
10
006 - Special computer methods
9
615 - Pharmacology & therapeutics
9
005 - Computer programming, programs & data
8
572 - Biochemistry
8
502 - Miscellany
7
539 - Modern physics
7
616 - Diseases
7
001 - Knowledge
6
155 - Differential & developmental psychology
6
363 - Other social problems & services
6
510 - Mathematics
6
537 - Electricity & electronics
6
599 - Mammals
6
658 - General management
6
300 - Social sciences
5
330 - Economics
5
332 - Financial economics
5
543 - Analytical chemistry
5
548 - Crystallography
5
629 - Other branches of engineering
5
003 - Systems
4
302 - Social interaction
4
343 - Military, tax, trade & industrial law
4
511 - General principles of mathematics
4
546 - Inorganic chemistry
4
571 - Physiology & related subjects
4
617 - Surgery & related medical specialties
4
153 - Mental processes & intelligence
3
301 - Sociology & anthropology
3
401 - Philosophy & theory
3
516 - Geometry
3
535 - Light & infrared & ultraviolet phenomena
3
709 - Historical, geographic & persons treatment
3
more ...