Classification
333 - Economics of land & energy
361 - Social problems & social welfare in general
620 - Engineering & allied operations
600 - Technology
3
330 - Economics
2
700 - The arts; fine & decorative arts
2
900 - History & geography
2
000 - Computer science, information & general works
1
140 - Specific philosophical schools
1
320 - Political science
1
363 - Other social problems & services
1
380 - Commerce, communications & transportation
1
576 - Genetics & evolution
1
610 - Medicine & health
1