Classification
303 - Social processes
3
500 - Natural sciences & mathematics
3
320 - Political science
2
321 - Systems of governments & states
2
140 - Specific philosophical schools
1
155 - Differential & developmental psychology
1
305 - Social groups
1
327 - International relations
1
333 - Economics of land & energy
1
354 - Administration of economy & environment
1
363 - Other social problems & services
1
658 - General management
1
900 - History & geography
1
972 - Middle America; Mexico
1