Classification
333 - Economics of land & energy
338 - Production
110
320 - Political science
18
621 - Applied physics
13
330 - Economics
9
363 - Other social problems & services
5
610 - Medicine & health
5
304 - Factors affecting social behavior
4
380 - Commerce, communications & transportation
3
302 - Social interaction
2
100 - Philosophy & psychology
1
332 - Financial economics
1
336 - Public finance
1
340 - Law
1
600 - Technology
1
602 - Miscellany
1
630 - Agriculture & related technologies
1
900 - History & geography
1