Classification
200 - Religion
333 - Economics of land & energy
600 - Technology
100 - Philosophy & psychology
1
170 - Ethics
1
300 - Social sciences
1
304 - Factors affecting social behavior
1
320 - Political science
1
330 - Economics
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1
610 - Medicine & health
1