Classification
304 - Factors affecting social behavior
363 - Other social problems & services
7
320 - Political science
5
330 - Economics
4
333 - Economics of land & energy
4
551 - Geology, hydrology & meteorology
3
000 - Computer science, information & general works
2
581 - Specific topics in natural history
2
600 - Technology
2
630 - Agriculture & related technologies
2
700 - The arts; fine & decorative arts
2
140 - Specific philosophical schools
1
300 - Social sciences
1
361 - Social problems & social welfare in general
1
370 - Education
1
380 - Commerce, communications & transportation
1
576 - Genetics & evolution
1
610 - Medicine & health
1
620 - Engineering & allied operations
1