Classification
000 - Computer science, information & general works
380 - Commerce, communications & transportation
333 - Economics of land & energy
13
700 - The arts; fine & decorative arts
13
620 - Engineering & allied operations
8
600 - Technology
7
363 - Other social problems & services
6
551 - Geology, hydrology & meteorology
6
610 - Medicine & health
6
140 - Specific philosophical schools
5
500 - Natural sciences & mathematics
5
530 - Physics
5
540 - Chemistry & allied sciences
5
576 - Genetics & evolution
5
580 - Plants (Botany)
5
320 - Political science
4
414 - Phonology & phonetics
4
612 - Human physiology
4
300 - Social sciences
3
330 - Economics
3
581 - Specific topics in natural history
3
900 - History & geography
3
100 - Philosophy & psychology
2
304 - Factors affecting social behavior
2
340 - Law
2
120 - Epistemology, causation & humankind
1
370 - Education
1
400 - Language
1
550 - Earth sciences
1
658 - General management
1
720 - Architecture
1
800 - Literature & rhetoric
1