Classification
300 - Social sciences
320 - Political science
363 - Other social problems & services
900 - History & geography
330 - Economics
6
333 - Economics of land & energy
5
600 - Technology
5
581 - Specific topics in natural history
4
000 - Computer science, information & general works
3
620 - Engineering & allied operations
3
100 - Philosophy & psychology
2
140 - Specific philosophical schools
2
304 - Factors affecting social behavior
2
380 - Commerce, communications & transportation
2
576 - Genetics & evolution
2
610 - Medicine & health
2
200 - Religion
1
301 - Sociology & anthropology
1
350 - Public administration & military science
1
370 - Education
1
580 - Plants (Botany)
1
630 - Agriculture & related technologies
1
700 - The arts; fine & decorative arts
1
720 - Architecture
1
800 - Literature & rhetoric
1