Classification
100 - Philosophy & psychology
140 - Specific philosophical schools
600 - Technology
170 - Ethics
2
320 - Political science
2
620 - Engineering & allied operations
2
000 - Computer science, information & general works
1
200 - Religion
1
301 - Sociology & anthropology
1
333 - Economics of land & energy
1
363 - Other social problems & services
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1
630 - Agriculture & related technologies
1