Classification
320 - Political science
333 - Economics of land & energy
160
330 - Economics
127
363 - Other social problems & services
57
304 - Factors affecting social behavior
42
610 - Medicine & health
42
600 - Technology
27
370 - Education
17
336 - Public finance
15
380 - Commerce, communications & transportation
15
630 - Agriculture & related technologies
14