Classification
333 - Economics of land & energy
363 - Other social problems & services
900 - History & geography
5
600 - Technology
4
620 - Engineering & allied operations
4
414 - Phonology & phonetics
3
576 - Genetics & evolution
3
580 - Plants (Botany)
3
700 - The arts; fine & decorative arts
3
000 - Computer science, information & general works
2
330 - Economics
2
304 - Factors affecting social behavior
1
380 - Commerce, communications & transportation
1