Classification
540 - Chemistry & allied sciences
000 - Computer science, information & general works
5
363 - Other social problems & services
4
580 - Plants (Botany)
4
333 - Economics of land & energy
3
600 - Technology
3
900 - History & geography
3
414 - Phonology & phonetics
2
551 - Geology, hydrology & meteorology
2
581 - Specific topics in natural history
2
620 - Engineering & allied operations
2
304 - Factors affecting social behavior
1
320 - Political science
1
330 - Economics
1
630 - Agriculture & related technologies
1
700 - The arts; fine & decorative arts
1