Classification
300 - Social sciences
320 - Political science
333 - Economics of land & energy
1
370 - Education
380 - Commerce, communications & transportation
1
400 - Language
1
500 - Natural sciences & mathematics
1
540 - Chemistry & allied sciences
1
600 - Technology
1
610 - Medicine & health
1
620 - Engineering & allied operations
1
900 - History & geography
1