Classification
300 - Social sciences
301 - Sociology & anthropology
333 - Economics of land & energy
320 - Political science
3
610 - Medicine & health
3
900 - History & geography
3
100 - Philosophy & psychology
2
330 - Economics
2
140 - Specific philosophical schools
1
340 - Law
1
370 - Education
1
581 - Specific topics in natural history
1
600 - Technology
1