Classification
330 - Economics
576 - Genetics & evolution
600 - Technology
900 - History & geography
620 - Engineering & allied operations
23
700 - The arts; fine & decorative arts
17
333 - Economics of land & energy
12
000 - Computer science, information & general works
10
380 - Commerce, communications & transportation
6
720 - Architecture
6
363 - Other social problems & services
5
610 - Medicine & health
5
140 - Specific philosophical schools
4
500 - Natural sciences & mathematics
4
658 - General management
4
100 - Philosophy & psychology
3
300 - Social sciences
3
320 - Political science
3
340 - Law
3
580 - Plants (Botany)
3
800 - Literature & rhetoric
3
370 - Education
2
400 - Language
2
630 - Agriculture & related technologies
2
200 - Religion
1
301 - Sociology & anthropology
1
304 - Factors affecting social behavior
1
350 - Public administration & military science
1
414 - Phonology & phonetics
1
530 - Physics
1
540 - Chemistry & allied sciences
1
581 - Specific topics in natural history
1