Classification
330 - Economics
228
333 - Economics of land & energy
166
320 - Political science
128
304 - Factors affecting social behavior
108
610 - Medicine & health
108
370 - Education
85
363 - Other social problems & services
61
600 - Technology
38
380 - Commerce, communications & transportation
37
336 - Public finance
33
630 - Agriculture & related technologies
19