Classification
344 - Labor, social, education & cultural law
246
333 - Economics of land & energy
173
363 - Other social problems & services
150
340 - Law
65
341 - Law of nations
52
304 - Factors affecting social behavior
45
577 - Ecology
39
551 - Geology, hydrology & meteorology
27
628 - Sanitary & municipal engineering
24
338 - Production
23
320 - Political science
18
621 - Applied physics
16
343 - Military, tax, trade & industrial law
15
330 - Economics
14
630 - Agriculture & related technologies
12
342 - Constitutional & administrative law
11
346 - Private law
11
910 - Geography & travel
11
658 - General management
10
550 - Earth sciences
9
634 - Orchards, fruits & forestry
9
364 - Criminology
8
327 - International relations
7
624 - Civil engineering
7
700 - The arts; fine & decorative arts
6
140 - Specific philosophical schools
5
660 - Chemical engineering
5
170 - Ethics
4
581 - Specific topics in natural history
4
620 - Engineering & allied operations
4
000 - Computer science, information & general works
3
300 - Social sciences
3
507 - Education, research & related topics
3
600 - Technology
3
629 - Other branches of engineering
3
301 - Sociology & anthropology
2
307 - Communities
2
500 - Natural sciences & mathematics
2
613 - Personal health & safety
2
631 - Techniques, equipment & materials
2
636 - Animal husbandry
2
650 - Management & auxiliary services
2
690 - Buildings
2
710 - Civic & landscape art
2
720 - Architecture
2
900 - History & geography
2
003 - Systems
1
305 - Social groups
1
336 - Public finance
1
339 - Macroeconomics & related topics
1
more ...