Classification
630 - Agriculture & related technologies
363 - Other social problems & services
4
700 - The arts; fine & decorative arts
4
000 - Computer science, information & general works
3
333 - Economics of land & energy
3
551 - Geology, hydrology & meteorology
3
600 - Technology
3
620 - Engineering & allied operations
3
304 - Factors affecting social behavior
2
330 - Economics
2
530 - Physics
2
140 - Specific philosophical schools
1
361 - Social problems & social welfare in general
1
370 - Education
1
380 - Commerce, communications & transportation
1
500 - Natural sciences & mathematics
1
540 - Chemistry & allied sciences
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
610 - Medicine & health
1
658 - General management
1
900 - History & geography
1