Classification
330 - Economics
363 - Other social problems & services
380 - Commerce, communications & transportation
600 - Technology
700 - The arts; fine & decorative arts
720 - Architecture
900 - History & geography
7
000 - Computer science, information & general works
5
333 - Economics of land & energy
5
370 - Education
5
140 - Specific philosophical schools
4
320 - Political science
4
551 - Geology, hydrology & meteorology
4
620 - Engineering & allied operations
4
610 - Medicine & health
3
658 - General management
2
400 - Language
1
576 - Genetics & evolution
1
580 - Plants (Botany)
1