Classification
330 - Economics
105
500 - Natural sciences & mathematics
70
620 - Engineering & allied operations
61
004 - Data processing & computer science
57
005 - Computer programming, programs & data
55
616 - Diseases
53
621 - Applied physics
50
320 - Political science
49
577 - Ecology
46
006 - Special computer methods
41
510 - Mathematics
41
551 - Geology, hydrology & meteorology
41
300 - Social sciences
39
520 - Astronomy & allied sciences
36
900 - History & geography
36
501 - Philosophy & theory
34
530 - Physics
34
519 - Probabilities & applied mathematics
33
617 - Surgery & related medical specialties
32
658 - General management
32
340 - Law
29
580 - Plants (Botany)
29
664 - Food technology
27
333 - Economics of land & energy
26
610 - Medicine & health
26
641 - Food & drink
24
338 - Production
23
550 - Earth sciences
23
306 - Culture & institutions
22
304 - Factors affecting social behavior
19
050 - General serial publications
18
570 - Life sciences; biology
18
910 - Geography & travel
18
331 - Labor economics
17
301 - Sociology & anthropology
16
302 - Social interaction
16
363 - Other social problems & services
16
509 - Historical, geographic & persons treatment
15
624 - Civil engineering
15
650 - Management & auxiliary services
15
541 - Physical chemistry
14
612 - Human physiology
14
576 - Genetics & evolution
13
600 - Technology
13
572 - Biochemistry
12
660 - Chemical engineering
12
515 - Analysis
11
523 - Specific celestial bodies & phenomena
11
571 - Physiology & related subjects
11
615 - Pharmacology & therapeutics
11
more ...