Classification
330 - Economics
105
300 - Social sciences
76
500 - Natural sciences & mathematics
75
004 - Data processing & computer science
63
616 - Diseases
63
620 - Engineering & allied operations
61
621 - Applied physics
58
005 - Computer programming, programs & data
56
577 - Ecology
56
320 - Political science
55
006 - Special computer methods
47
510 - Mathematics
43
551 - Geology, hydrology & meteorology
43
001 - Knowledge
41
333 - Economics of land & energy
41
501 - Philosophy & theory
37
900 - History & geography
36
617 - Surgery & related medical specialties
35
610 - Medicine & health
33
580 - Plants (Botany)
31
658 - General management
30
520 - Astronomy & allied sciences
29
550 - Earth sciences
27
664 - Food technology
27
641 - Food & drink
25
301 - Sociology & anthropology
24
340 - Law
24
363 - Other social problems & services
24
519 - Probabilities & applied mathematics
24
530 - Physics
24
910 - Geography & travel
24
304 - Factors affecting social behavior
22
306 - Culture & institutions
21
338 - Production
21
331 - Labor economics
18
570 - Life sciences; biology
18
509 - Historical, geographic & persons treatment
17
576 - Genetics & evolution
17
302 - Social interaction
15
571 - Physiology & related subjects
15
612 - Human physiology
15
624 - Civil engineering
15
650 - Management & auxiliary services
14
327 - International relations
13
572 - Biochemistry
13
600 - Technology
13
511 - General principles of mathematics
12
670 - Manufacturing
12
303 - Social processes
11
515 - Analysis
11
more ...