Classification
100 - Philosophy & psychology
170 - Ethics
320 - Political science
7
900 - History & geography
4
120 - Epistemology, causation & humankind
3
140 - Specific philosophical schools
3
200 - Religion
3
333 - Economics of land & energy
2
370 - Education
2
380 - Commerce, communications & transportation
2
400 - Language
2
600 - Technology
2
160 - Logic
1
300 - Social sciences
1
363 - Other social problems & services
1
551 - Geology, hydrology & meteorology
1