Classification
330 - Economics
3
333 - Economics of land & energy
610 - Medicine & health
630 - Agriculture & related technologies
363 - Other social problems & services
2
600 - Technology
2
620 - Engineering & allied operations
2
140 - Specific philosophical schools
1
380 - Commerce, communications & transportation
1
540 - Chemistry & allied sciences
1
551 - Geology, hydrology & meteorology
1
580 - Plants (Botany)
1
581 - Specific topics in natural history
1