Classification
600 - Technology
363 - Other social problems & services
3
620 - Engineering & allied operations
3
900 - History & geography
3
320 - Political science
2
333 - Economics of land & energy
2
700 - The arts; fine & decorative arts
2
140 - Specific philosophical schools
1
330 - Economics
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1