Classification
551 - Geology, hydrology & meteorology
900 - History & geography
363 - Other social problems & services
6
700 - The arts; fine & decorative arts
5
140 - Specific philosophical schools
4
300 - Social sciences
4
720 - Architecture
3
330 - Economics
2
333 - Economics of land & energy
2
500 - Natural sciences & mathematics
2
581 - Specific topics in natural history
2
600 - Technology
2
610 - Medicine & health
2
100 - Philosophy & psychology
1
120 - Epistemology, causation & humankind
1
320 - Political science
1
350 - Public administration & military science
1
370 - Education
1
620 - Engineering & allied operations
1
800 - Literature & rhetoric
1