Classification
330 - Economics
370 - Education
333 - Economics of land & energy
5
363 - Other social problems & services
5
320 - Political science
3
380 - Commerce, communications & transportation
3
600 - Technology
3
700 - The arts; fine & decorative arts
3
900 - History & geography
3
140 - Specific philosophical schools
2
610 - Medicine & health
2
620 - Engineering & allied operations
2
300 - Social sciences
1
304 - Factors affecting social behavior
1
551 - Geology, hydrology & meteorology
1