Classification
333 - Economics of land & energy
2
361 - Social problems & social welfare in general
380 - Commerce, communications & transportation
610 - Medicine & health
2
700 - The arts; fine & decorative arts
140 - Specific philosophical schools
1
304 - Factors affecting social behavior
1
320 - Political science
1
363 - Other social problems & services
1
400 - Language
1