Classification
330 - Economics
370 - Education
333 - Economics of land & energy
25
363 - Other social problems & services
20
600 - Technology
19
700 - The arts; fine & decorative arts
17
320 - Political science
15
380 - Commerce, communications & transportation
14
000 - Computer science, information & general works
13
610 - Medicine & health
12
551 - Geology, hydrology & meteorology
11
900 - History & geography
10
140 - Specific philosophical schools
8
620 - Engineering & allied operations
7
720 - Architecture
4
304 - Factors affecting social behavior
3
340 - Law
3
400 - Language
3
658 - General management
3
100 - Philosophy & psychology
2
200 - Religion
2
300 - Social sciences
2
360 - Social problems & services; associations
2
410 - Linguistics
2
414 - Phonology & phonetics
2
500 - Natural sciences & mathematics
2
160 - Logic
1
170 - Ethics
1
350 - Public administration & military science
1
550 - Earth sciences
1
576 - Genetics & evolution
1
581 - Specific topics in natural history
1
630 - Agriculture & related technologies
1
657 - Accounting
1
780 - Music
1