Classification
414 - Phonology & phonetics
500 - Natural sciences & mathematics
620 - Engineering & allied operations
700 - The arts; fine & decorative arts
7
600 - Technology
6
900 - History & geography
6
333 - Economics of land & energy
5
000 - Computer science, information & general works
4
580 - Plants (Botany)
4
610 - Medicine & health
4
140 - Specific philosophical schools
3
300 - Social sciences
3
363 - Other social problems & services
3
380 - Commerce, communications & transportation
3
540 - Chemistry & allied sciences
3
551 - Geology, hydrology & meteorology
3
576 - Genetics & evolution
3
581 - Specific topics in natural history
3
612 - Human physiology
3
330 - Economics
2
304 - Factors affecting social behavior
1
320 - Political science
1
340 - Law
1
530 - Physics
1