Classification
304 - Factors affecting social behavior
2
333 - Economics of land & energy
363 - Other social problems & services
2
414 - Phonology & phonetics
2
551 - Geology, hydrology & meteorology
2
900 - History & geography
2
000 - Computer science, information & general works
1
610 - Medicine & health
1
615 - Pharmacology & therapeutics
1