Classification
170 - Ethics
330 - Economics
5
551 - Geology, hydrology & meteorology
363 - Other social problems & services
4
100 - Philosophy & psychology
3
320 - Political science
2
000 - Computer science, information & general works
1
300 - Social sciences
1
333 - Economics of land & energy
1
370 - Education
1
500 - Natural sciences & mathematics
1
600 - Technology
1
610 - Medicine & health
1
620 - Engineering & allied operations
1
720 - Architecture
1
900 - History & geography
1