Classification
140 - Specific philosophical schools
900 - History & geography
14
620 - Engineering & allied operations
9
700 - The arts; fine & decorative arts
9
363 - Other social problems & services
8
500 - Natural sciences & mathematics
7
540 - Chemistry & allied sciences
7
720 - Architecture
7
000 - Computer science, information & general works
6
590 - Animals (Zoology)
6
581 - Specific topics in natural history
5
330 - Economics
4
333 - Economics of land & energy
4
600 - Technology
4
530 - Physics
3
100 - Philosophy & psychology
2
301 - Sociology & anthropology
2
380 - Commerce, communications & transportation
2
551 - Geology, hydrology & meteorology
2
580 - Plants (Botany)
2
610 - Medicine & health
2
170 - Ethics
1
200 - Religion
1
300 - Social sciences
1
304 - Factors affecting social behavior
1
320 - Political science
1
340 - Law
1
576 - Genetics & evolution
1
800 - Literature & rhetoric
1