Classification
540 - Chemistry & allied sciences
370 - Education
6
600 - Technology
5
330 - Economics
4
363 - Other social problems & services
3
000 - Computer science, information & general works
2
380 - Commerce, communications & transportation
2
620 - Engineering & allied operations
2
140 - Specific philosophical schools
1
333 - Economics of land & energy
1
500 - Natural sciences & mathematics
1
542 - Techniques, equipment & materials
1
551 - Geology, hydrology & meteorology
1
612 - Human physiology
1
660 - Chemical engineering
1