Classification
330 - Economics
35
616 - Diseases
28
620 - Engineering & allied operations
19
617 - Surgery & related medical specialties
15
006 - Special computer methods
14
306 - Culture & institutions
13
510 - Mathematics
13
577 - Ecology
12
500 - Natural sciences & mathematics
11
621 - Applied physics
11
005 - Computer programming, programs & data
10
338 - Production
10
519 - Probabilities & applied mathematics
10
520 - Astronomy & allied sciences
10
331 - Labor economics
9
333 - Economics of land & energy
9
501 - Philosophy & theory
9
551 - Geology, hydrology & meteorology
9
004 - Data processing & computer science
8
320 - Political science
8
658 - General management
8
300 - Social sciences
7
610 - Medicine & health
7
509 - Historical, geographic & persons treatment
6
515 - Analysis
6
576 - Genetics & evolution
6
808 - Rhetoric & collections of literature
6
809 - History, description & criticism
6
001 - Knowledge
5
304 - Factors affecting social behavior
5
618 - Gynecology, obstetrics, pediatrics & geriatrics
5
629 - Other branches of engineering
5
660 - Chemical engineering
5
327 - International relations
4
332 - Financial economics
4
340 - Law
4
363 - Other social problems & services
4
530 - Physics
4
571 - Physiology & related subjects
4
572 - Biochemistry
4
900 - History & geography
4
930 - History of ancient world to ca. 499
4
003 - Systems
3
100 - Philosophy & psychology
3
109 - Historical & collected persons treatment
3
384 - Communications; telecommunication
3
511 - General principles of mathematics
3
516 - Geometry
3
531 - Classical mechanics; solid mechanics
3
547 - Organic chemistry
3
more ...