Classification
330 - Economics
363 - Other social problems & services
380 - Commerce, communications & transportation
600 - Technology
900 - History & geography
620 - Engineering & allied operations
24
333 - Economics of land & energy
20
700 - The arts; fine & decorative arts
20
000 - Computer science, information & general works
13
370 - Education
9
720 - Architecture
8
551 - Geology, hydrology & meteorology
7
140 - Specific philosophical schools
6
320 - Political science
6
610 - Medicine & health
4
658 - General management
4
340 - Law
3
400 - Language
3
580 - Plants (Botany)
3
200 - Religion
2
304 - Factors affecting social behavior
2
576 - Genetics & evolution
2
657 - Accounting
2
800 - Literature & rhetoric
2
300 - Social sciences
1
410 - Linguistics
1
530 - Physics
1
581 - Specific topics in natural history
1