Classification
333 - Economics of land & energy
610 - Medicine & health
18
330 - Economics
7
363 - Other social problems & services
5
615 - Pharmacology & therapeutics
4
140 - Specific philosophical schools
3
362 - Social welfare problems & services
3
700 - The arts; fine & decorative arts
3
000 - Computer science, information & general works
2
361 - Social problems & social welfare in general
2
551 - Geology, hydrology & meteorology
2
576 - Genetics & evolution
2
600 - Technology
2
612 - Human physiology
2
100 - Philosophy & psychology
1
320 - Political science
1
370 - Education
1
540 - Chemistry & allied sciences
1
625 - Engineering of railroads & roads
1