Classification
330 - Economics
333 - Economics of land & energy
320 - Political science
459
363 - Other social problems & services
193
304 - Factors affecting social behavior
121
610 - Medicine & health
121
380 - Commerce, communications & transportation
81
600 - Technology
64
370 - Education
47
336 - Public finance
36
630 - Agriculture & related technologies
32
340 - Law
4