Classification
320 - Political science
330 - Economics
380 - Commerce, communications & transportation
600 - Technology
700 - The arts; fine & decorative arts
900 - History & geography
333 - Economics of land & energy
6
370 - Education
5
620 - Engineering & allied operations
5
363 - Other social problems & services
4
000 - Computer science, information & general works
3
551 - Geology, hydrology & meteorology
3
610 - Medicine & health
3
720 - Architecture
3
100 - Philosophy & psychology
2
300 - Social sciences
2
304 - Factors affecting social behavior
2
400 - Language
2
630 - Agriculture & related technologies
2
658 - General management
2
780 - Music
2
140 - Specific philosophical schools
1
200 - Religion
1
340 - Law
1
410 - Linguistics
1
576 - Genetics & evolution
1
580 - Plants (Botany)
1
581 - Specific topics in natural history
1