Classification
304 - Factors affecting social behavior
610 - Medicine & health
2,517
330 - Economics
955
333 - Economics of land & energy
322
320 - Political science
303
370 - Education
217
363 - Other social problems & services
137
600 - Technology
131
380 - Commerce, communications & transportation
54
630 - Agriculture & related technologies
33
336 - Public finance
30
340 - Law
3