Classification
330 - Economics
709
333 - Economics of land & energy
89
320 - Political science
27
370 - Education
23
380 - Commerce, communications & transportation
20
600 - Technology
16
363 - Other social problems & services
15
336 - Public finance
13
630 - Agriculture & related technologies
13
304 - Factors affecting social behavior
6
610 - Medicine & health
6