Classification
320 - Political science
330 - Economics
333 - Economics of land & energy
363 - Other social problems & services
580 - Plants (Botany)
600 - Technology
5
000 - Computer science, information & general works
4
551 - Geology, hydrology & meteorology
4
620 - Engineering & allied operations
4
630 - Agriculture & related technologies
4
700 - The arts; fine & decorative arts
3
361 - Social problems & social welfare in general
2
380 - Commerce, communications & transportation
2
610 - Medicine & health
2
658 - General management
2
720 - Architecture
2
900 - History & geography
2
100 - Philosophy & psychology
1
140 - Specific philosophical schools
1
336 - Public finance
1
340 - Law
1
370 - Education
1
520 - Astronomy & allied sciences
1
581 - Specific topics in natural history
1
800 - Literature & rhetoric
1