Classification
005 - Computer programming, programs & data
88
330 - Economics
71
333 - Economics of land & energy
29
331 - Labor economics
26
004 - Data processing & computer science
25
551 - Geology, hydrology & meteorology
24
616 - Diseases
24
658 - General management
21
610 - Medicine & health
19
304 - Factors affecting social behavior
18
338 - Production
17
363 - Other social problems & services
16
006 - Special computer methods
14
577 - Ecology
14
374 - Adult education
13
620 - Engineering & allied operations
13
630 - Agriculture & related technologies
12
500 - Natural sciences & mathematics
11
621 - Applied physics
10
910 - Geography & travel
10
300 - Social sciences
8
384 - Communications; telecommunication
8
550 - Earth sciences
8
306 - Culture & institutions
7
618 - Gynecology, obstetrics, pediatrics & geriatrics
7
000 - Computer science, information & general works
6
301 - Sociology & anthropology
6
571 - Physiology & related subjects
6
302 - Social interaction
5
320 - Political science
5
613 - Personal health & safety
5
700 - The arts; fine & decorative arts
5
332 - Financial economics
4
364 - Criminology
4
370 - Education
4
670 - Manufacturing
4
003 - Systems
3
158 - Applied psychology
3
174 - Occupational ethics
3
305 - Social groups
3
307 - Communities
3
342 - Constitutional & administrative law
3
380 - Commerce, communications & transportation
3
519 - Probabilities & applied mathematics
3
612 - Human physiology
3
624 - Civil engineering
3
631 - Techniques, equipment & materials
3
660 - Chemical engineering
3
100 - Philosophy & psychology
2
150 - Psychology
2
more ...