Classification
330 - Economics
189
361 - Social problems & social welfare in general
118
320 - Political science
56
338 - Production
37
302 - Social interaction
35
610 - Medicine & health
35
300 - Social sciences
19
100 - Philosophy & psychology
14
304 - Factors affecting social behavior
13
336 - Public finance
12
333 - Economics of land & energy
11
340 - Law
10
301 - Sociology & anthropology
9
658 - General management
9
331 - Labor economics
8
306 - Culture & institutions
7
339 - Macroeconomics & related topics
6
370 - Education
6
305 - Social groups
5
170 - Ethics
4
174 - Occupational ethics
4
307 - Communities
4
360 - Social problems & services; associations
4
337 - International economics
3
350 - Public administration & military science
3
519 - Probabilities & applied mathematics
3
700 - The arts; fine & decorative arts
3
140 - Specific philosophical schools
2
327 - International relations
2
363 - Other social problems & services
2
364 - Criminology
2
371 - Schools & their activities; special education
2
615 - Pharmacology & therapeutics
2
621 - Applied physics
2
900 - History & geography
2
000 - Computer science, information & general works
1
006 - Special computer methods
1
303 - Social processes
1
323 - Civil & political rights
1
332 - Financial economics
1
343 - Military, tax, trade & industrial law
1
368 - Insurance
1
378 - Higher education
1
380 - Commerce, communications & transportation
1
530 - Physics
1
551 - Geology, hydrology & meteorology
1
571 - Physiology & related subjects
1
577 - Ecology
1
613 - Personal health & safety
1
614 - Incidence & prevention of disease
1
more ...