Classification
320 - Political science
581 - Specific topics in natural history
600 - Technology
700 - The arts; fine & decorative arts
900 - History & geography
333 - Economics of land & energy
3
363 - Other social problems & services
3
620 - Engineering & allied operations
3
000 - Computer science, information & general works
2
140 - Specific philosophical schools
2
330 - Economics
2
370 - Education
2
380 - Commerce, communications & transportation
2
170 - Ethics
1
200 - Religion
1
301 - Sociology & anthropology
1
361 - Social problems & social welfare in general
1
530 - Physics
1
610 - Medicine & health
1