Classification
330 - Economics
600 - Technology
700 - The arts; fine & decorative arts
320 - Political science
2
333 - Economics of land & energy
2
363 - Other social problems & services
2
576 - Genetics & evolution
2
900 - History & geography
2
140 - Specific philosophical schools
1
200 - Religion
1
304 - Factors affecting social behavior
1
380 - Commerce, communications & transportation
1
551 - Geology, hydrology & meteorology
1
620 - Engineering & allied operations
1
630 - Agriculture & related technologies
1