Classification
320 - Political science
363 - Other social problems & services
581 - Specific topics in natural history
330 - Economics
7
140 - Specific philosophical schools
6
333 - Economics of land & energy
5
300 - Social sciences
4
600 - Technology
4
551 - Geology, hydrology & meteorology
3
700 - The arts; fine & decorative arts
3
340 - Law
2
100 - Philosophy & psychology
1
170 - Ethics
1
380 - Commerce, communications & transportation
1
630 - Agriculture & related technologies
1
900 - History & geography
1