Classification
320 - Political science
380 - Commerce, communications & transportation
600 - Technology
620 - Engineering & allied operations
900 - History & geography
25
700 - The arts; fine & decorative arts
18
333 - Economics of land & energy
13
363 - Other social problems & services
12
000 - Computer science, information & general works
11
330 - Economics
11
140 - Specific philosophical schools
7
300 - Social sciences
7
340 - Law
7
720 - Architecture
7
500 - Natural sciences & mathematics
6
370 - Education
5
400 - Language
5
551 - Geology, hydrology & meteorology
5
100 - Philosophy & psychology
4
576 - Genetics & evolution
4
610 - Medicine & health
4
630 - Agriculture & related technologies
3
658 - General management
3
780 - Music
3
170 - Ethics
2
410 - Linguistics
2
550 - Earth sciences
2
580 - Plants (Botany)
2
581 - Specific topics in natural history
2
657 - Accounting
2
540 - Chemistry & allied sciences
1
800 - Literature & rhetoric
1