Classification
000 - Computer science, information & general works
540 - Chemistry & allied sciences
630 - Agriculture & related technologies
700 - The arts; fine & decorative arts
333 - Economics of land & energy
6
610 - Medicine & health
5
330 - Economics
4
363 - Other social problems & services
4
620 - Engineering & allied operations
4
320 - Political science
3
551 - Geology, hydrology & meteorology
3
600 - Technology
3
140 - Specific philosophical schools
2
380 - Commerce, communications & transportation
2
300 - Social sciences
1
304 - Factors affecting social behavior
1
361 - Social problems & social welfare in general
1
370 - Education
1
400 - Language
1
414 - Phonology & phonetics
1
500 - Natural sciences & mathematics
1
530 - Physics
1
581 - Specific topics in natural history
1
612 - Human physiology
1
900 - History & geography
1