Classification
630 - Agriculture & related technologies
333 - Economics of land & energy
3
330 - Economics
2
380 - Commerce, communications & transportation
2
700 - The arts; fine & decorative arts
2
320 - Political science
1
340 - Law
1
363 - Other social problems & services
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
720 - Architecture
1