Classification
330 - Economics
2
363 - Other social problems & services
540 - Chemistry & allied sciences
581 - Specific topics in natural history
000 - Computer science, information & general works
1
320 - Political science
1
333 - Economics of land & energy
1
520 - Astronomy & allied sciences
1
600 - Technology
1
620 - Engineering & allied operations
1
700 - The arts; fine & decorative arts
1
900 - History & geography
1