Classification
300 - Social sciences
380 - Commerce, communications & transportation
500 - Natural sciences & mathematics
600 - Technology
320 - Political science
3
370 - Education
3
620 - Engineering & allied operations
3
900 - History & geography
2
000 - Computer science, information & general works
1
100 - Philosophy & psychology
1
330 - Economics
1
333 - Economics of land & energy
1
400 - Language
1
540 - Chemistry & allied sciences
1
610 - Medicine & health
1
630 - Agriculture & related technologies
1