Classification
333 - Economics of land & energy
320 - Political science
52
330 - Economics
30
304 - Factors affecting social behavior
23
610 - Medicine & health
23
363 - Other social problems & services
13
370 - Education
11
600 - Technology
6
380 - Commerce, communications & transportation
5
336 - Public finance
2
630 - Agriculture & related technologies
1