Classification
140 - Specific philosophical schools
333 - Economics of land & energy
2
363 - Other social problems & services
551 - Geology, hydrology & meteorology
700 - The arts; fine & decorative arts
2
900 - History & geography
2
000 - Computer science, information & general works
1
170 - Ethics
1
330 - Economics
1
580 - Plants (Botany)
1
581 - Specific topics in natural history
1
600 - Technology
1
620 - Engineering & allied operations
1