Classification
330 - Economics
2
600 - Technology
2
610 - Medicine & health
2
900 - History & geography
100 - Philosophy & psychology
1
300 - Social sciences
1
320 - Political science
1
333 - Economics of land & energy
1
350 - Public administration & military science
1
363 - Other social problems & services
1
370 - Education
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
620 - Engineering & allied operations
1
780 - Music
1