Classification
363 - Other social problems & services
551 - Geology, hydrology & meteorology
600 - Technology
330 - Economics
2
333 - Economics of land & energy
2
620 - Engineering & allied operations
2
500 - Natural sciences & mathematics
1
540 - Chemistry & allied sciences
1
581 - Specific topics in natural history
1
610 - Medicine & health
1
630 - Agriculture & related technologies
1
700 - The arts; fine & decorative arts
1