Classification
170 - Ethics
320 - Political science
900 - History & geography
330 - Economics
16
100 - Philosophy & psychology
15
700 - The arts; fine & decorative arts
11
300 - Social sciences
9
340 - Law
7
800 - Literature & rhetoric
7
140 - Specific philosophical schools
6
363 - Other social problems & services
5
600 - Technology
5
200 - Religion
4
333 - Economics of land & energy
4
370 - Education
4
620 - Engineering & allied operations
4
301 - Sociology & anthropology
3
304 - Factors affecting social behavior
3
000 - Computer science, information & general works
2
361 - Social problems & social welfare in general
2
400 - Language
2
581 - Specific topics in natural history
2
610 - Medicine & health
2
120 - Epistemology, causation & humankind
1
160 - Logic
1
380 - Commerce, communications & transportation
1
410 - Linguistics
1
520 - Astronomy & allied sciences
1
530 - Physics
1
551 - Geology, hydrology & meteorology
1
576 - Genetics & evolution
1
780 - Music
1