Classification
330 - Economics
76
333 - Economics of land & energy
30
600 - Technology
28
304 - Factors affecting social behavior
26
610 - Medicine & health
26
320 - Political science
23
380 - Commerce, communications & transportation
20
363 - Other social problems & services
17
370 - Education
6
336 - Public finance
5
630 - Agriculture & related technologies
5