Classification
320 - Political science
177
330 - Economics
143
333 - Economics of land & energy
91
304 - Factors affecting social behavior
79
610 - Medicine & health
79
370 - Education
75
600 - Technology
53
336 - Public finance
33
363 - Other social problems & services
31
380 - Commerce, communications & transportation
13
630 - Agriculture & related technologies
9