Classification
140 - Specific philosophical schools
620 - Engineering & allied operations
551 - Geology, hydrology & meteorology
3
600 - Technology
3
900 - History & geography
3
304 - Factors affecting social behavior
2
363 - Other social problems & services
2
380 - Commerce, communications & transportation
2
700 - The arts; fine & decorative arts
2
300 - Social sciences
1
320 - Political science
1
333 - Economics of land & energy
1
414 - Phonology & phonetics
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
610 - Medicine & health
1
630 - Agriculture & related technologies
1