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