Classification
600 - Technology
5
333 - Economics of land & energy
4
540 - Chemistry & allied sciences
4
000 - Computer science, information & general works
3
620 - Engineering & allied operations
3
700 - The arts; fine & decorative arts
3
900 - History & geography
3
363 - Other social problems & services
2
304 - Factors affecting social behavior
1
576 - Genetics & evolution
1