Classification
333 - Economics of land & energy
4
370 - Education
581 - Specific topics in natural history
900 - History & geography
320 - Political science
3
363 - Other social problems & services
3
600 - Technology
3
700 - The arts; fine & decorative arts
3
000 - Computer science, information & general works
2
330 - Economics
2
620 - Engineering & allied operations
2
140 - Specific philosophical schools
1
170 - Ethics
1
380 - Commerce, communications & transportation
1
414 - Phonology & phonetics
1
530 - Physics
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1