Classification
320 - Political science
333 - Economics of land & energy
6
600 - Technology
610 - Medicine & health
700 - The arts; fine & decorative arts
330 - Economics
5
363 - Other social problems & services
5
000 - Computer science, information & general works
4
380 - Commerce, communications & transportation
4
551 - Geology, hydrology & meteorology
4
900 - History & geography
3
370 - Education
2
620 - Engineering & allied operations
2
720 - Architecture
2
140 - Specific philosophical schools
1
340 - Law
1
361 - Social problems & social welfare in general
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
658 - General management
1