Classification
333 - Economics of land & energy
900 - History & geography
13
320 - Political science
7
330 - Economics
7
300 - Social sciences
4
600 - Technology
2
000 - Computer science, information & general works
1
100 - Philosophy & psychology
1
200 - Religion
1
363 - Other social problems & services
1
370 - Education
1
610 - Medicine & health
1