Classification
330 - Economics
363 - Other social problems & services
380 - Commerce, communications & transportation
414 - Phonology & phonetics
700 - The arts; fine & decorative arts
000 - Computer science, information & general works
3
320 - Political science
3
333 - Economics of land & energy
3
140 - Specific philosophical schools
2
370 - Education
2
551 - Geology, hydrology & meteorology
2
304 - Factors affecting social behavior
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
600 - Technology
1
610 - Medicine & health
1
900 - History & geography
1