Classification
900 - History & geography
32
370 - Education
15
700 - The arts; fine & decorative arts
12
300 - Social sciences
11
320 - Political science
11
800 - Literature & rhetoric
7
600 - Technology
6
100 - Philosophy & psychology
5
400 - Language
5
720 - Architecture
5
000 - Computer science, information & general works
4
304 - Factors affecting social behavior
4
333 - Economics of land & energy
4
340 - Law
4
363 - Other social problems & services
4
410 - Linguistics
4
576 - Genetics & evolution
4
610 - Medicine & health
4
140 - Specific philosophical schools
3
301 - Sociology & anthropology
3
330 - Economics
3
361 - Social problems & social welfare in general
2
380 - Commerce, communications & transportation
2
360 - Social problems & services; associations
1
398 - Folklore
1
520 - Astronomy & allied sciences
1
530 - Physics
1
620 - Engineering & allied operations
1
658 - General management
1