Classification
363 - Other social problems & services
580 - Plants (Botany)
4
581 - Specific topics in natural history
4
590 - Animals (Zoology)
3
600 - Technology
3
620 - Engineering & allied operations
3
333 - Economics of land & energy
2
630 - Agriculture & related technologies
2
140 - Specific philosophical schools
1
330 - Economics
1
610 - Medicine & health
1