Classification
581 - Specific topics in natural history
900 - History & geography
333 - Economics of land & energy
3
580 - Plants (Botany)
3
000 - Computer science, information & general works
2
363 - Other social problems & services
2
551 - Geology, hydrology & meteorology
2
630 - Agriculture & related technologies
2
500 - Natural sciences & mathematics
1
600 - Technology
1
620 - Engineering & allied operations
1
700 - The arts; fine & decorative arts
1