Classification
650 - Management & auxiliary services
6,626
658 - General management
2,469
616 - Diseases
1,463
005 - Computer programming, programs & data
1,269
330 - Economics
814
004 - Data processing & computer science
730
006 - Special computer methods
674
333 - Economics of land & energy
530
617 - Surgery & related medical specialties
496
577 - Ecology
447
621 - Applied physics
440
003 - Systems
434
620 - Engineering & allied operations
331
338 - Production
325
300 - Social sciences
317
610 - Medicine & health
305
363 - Other social problems & services
282
519 - Probabilities & applied mathematics
248
551 - Geology, hydrology & meteorology
230
001 - Knowledge
181
332 - Financial economics
163
629 - Other branches of engineering
162
618 - Gynecology, obstetrics, pediatrics & geriatrics
155
628 - Sanitary & municipal engineering
137
624 - Civil engineering
135
670 - Manufacturing
135
040 - [Unassigned]
130
613 - Personal health & safety
130
634 - Orchards, fruits & forestry
126
320 - Political science
124
630 - Agriculture & related technologies
112
571 - Physiology & related subjects
99
150 - Psychology
95
614 - Incidence & prevention of disease
92
657 - Accounting
92
301 - Sociology & anthropology
90
580 - Plants (Botany)
86
910 - Geography & travel
84
615 - Pharmacology & therapeutics
83
660 - Chemical engineering
67
336 - Public finance
66
371 - Schools & their activities; special education
66
690 - Buildings
63
370 - Education
62
381 - Commerce
62
337 - International economics
57
641 - Food & drink
55
664 - Food technology
55
550 - Earth sciences
54
304 - Factors affecting social behavior
47
more ...