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