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