Classification
551 - Geology, hydrology & meteorology
600 - Technology
3
620 - Engineering & allied operations
900 - History & geography
333 - Economics of land & energy
2
363 - Other social problems & services
2
630 - Agriculture & related technologies
2
540 - Chemistry & allied sciences
1
580 - Plants (Botany)
1
581 - Specific topics in natural history
1
612 - Human physiology
1
700 - The arts; fine & decorative arts
1