Classification
363 - Other social problems & services
600 - Technology
3
620 - Engineering & allied operations
000 - Computer science, information & general works
2
580 - Plants (Botany)
2
610 - Medicine & health
2
630 - Agriculture & related technologies
2
900 - History & geography
2
300 - Social sciences
1
304 - Factors affecting social behavior
1
320 - Political science
1
370 - Education
1
551 - Geology, hydrology & meteorology
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1