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