Classification
330 - Economics
363 - Other social problems & services
380 - Commerce, communications & transportation
551 - Geology, hydrology & meteorology
600 - Technology
900 - History & geography
333 - Economics of land & energy
6
700 - The arts; fine & decorative arts
5
620 - Engineering & allied operations
4
000 - Computer science, information & general works
3
720 - Architecture
3
320 - Political science
2
370 - Education
2
610 - Medicine & health
2
140 - Specific philosophical schools
1
530 - Physics
1
580 - Plants (Botany)
1