Classification
333 - Economics of land & energy
3
380 - Commerce, communications & transportation
3
580 - Plants (Botany)
3
600 - Technology
3
620 - Engineering & allied operations
3
630 - Agriculture & related technologies
3
700 - The arts; fine & decorative arts
000 - Computer science, information & general works
2
363 - Other social problems & services
2
610 - Medicine & health
2
330 - Economics
1
900 - History & geography
1