Classification
100 - Philosophy & psychology
170 - Ethics
320 - Political science
363 - Other social problems & services
330 - Economics
5
700 - The arts; fine & decorative arts
5
140 - Specific philosophical schools
4
333 - Economics of land & energy
4
340 - Law
4
551 - Geology, hydrology & meteorology
4
300 - Social sciences
3
581 - Specific topics in natural history
3
610 - Medicine & health
3
200 - Religion
2
900 - History & geography
2
361 - Social problems & social welfare in general
1
370 - Education
1
380 - Commerce, communications & transportation
1
500 - Natural sciences & mathematics
1
530 - Physics
1
600 - Technology
1
620 - Engineering & allied operations
1
630 - Agriculture & related technologies
1
658 - General management
1
800 - Literature & rhetoric
1