Classification
200 - Religion
300 - Social sciences
320 - Political science
330 - Economics
2
380 - Commerce, communications & transportation
600 - Technology
900 - History & geography
2
301 - Sociology & anthropology
1
304 - Factors affecting social behavior
1
340 - Law
1
363 - Other social problems & services
1
370 - Education
1
400 - Language
1