Classification
630 - Agriculture & related technologies
121
363 - Other social problems & services
41
333 - Economics of land & energy
27
330 - Economics
17
380 - Commerce, communications & transportation
17
320 - Political science
14
304 - Factors affecting social behavior
9
610 - Medicine & health
9
600 - Technology
5
370 - Education
3
336 - Public finance
1
340 - Law
1