Classification
330 - Economics
551 - Geology, hydrology & meteorology
363 - Other social problems & services
5
333 - Economics of land & energy
4
320 - Political science
3
700 - The arts; fine & decorative arts
2
900 - History & geography
2
140 - Specific philosophical schools
1
340 - Law
1
380 - Commerce, communications & transportation
1
550 - Earth sciences
1
581 - Specific topics in natural history
1
600 - Technology
1
620 - Engineering & allied operations
1
720 - Architecture
1