Classification
600 - Technology
1,740
330 - Economics
629
370 - Education
347
320 - Political science
288
333 - Economics of land & energy
209
304 - Factors affecting social behavior
151
610 - Medicine & health
151
363 - Other social problems & services
124
380 - Commerce, communications & transportation
63
630 - Agriculture & related technologies
49
336 - Public finance
21