Classification
363 - Other social problems & services
333 - Economics of land & energy
560
330 - Economics
527
320 - Political science
361
380 - Commerce, communications & transportation
210
630 - Agriculture & related technologies
196
304 - Factors affecting social behavior
137
610 - Medicine & health
137
600 - Technology
98
336 - Public finance
72
370 - Education
36