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