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