Classification
140 - Specific philosophical schools
363 - Other social problems & services
551 - Geology, hydrology & meteorology
600 - Technology
620 - Engineering & allied operations
7
900 - History & geography
700 - The arts; fine & decorative arts
5
380 - Commerce, communications & transportation
4
333 - Economics of land & energy
3
304 - Factors affecting social behavior
1
330 - Economics
1
576 - Genetics & evolution
1
580 - Plants (Botany)
1
581 - Specific topics in natural history
1
630 - Agriculture & related technologies
1
720 - Architecture
1