Classification
320 - Political science
333 - Economics of land & energy
5
600 - Technology
900 - History & geography
363 - Other social problems & services
4
380 - Commerce, communications & transportation
4
610 - Medicine & health
4
700 - The arts; fine & decorative arts
4
330 - Economics
3
370 - Education
3
620 - Engineering & allied operations
3
551 - Geology, hydrology & meteorology
2
720 - Architecture
2
000 - Computer science, information & general works
1
100 - Philosophy & psychology
1
140 - Specific philosophical schools
1
300 - Social sciences
1
400 - Language
1
500 - Natural sciences & mathematics
1
540 - Chemistry & allied sciences
1
581 - Specific topics in natural history
1
630 - Agriculture & related technologies
1