Classification
500 - Natural sciences & mathematics
700 - The arts; fine & decorative arts
333 - Economics of land & energy
1
363 - Other social problems & services
1
530 - Physics
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1
600 - Technology
1
620 - Engineering & allied operations
1
630 - Agriculture & related technologies
1
900 - History & geography
1