Classification
333 - Economics of land & energy
7
530 - Physics
600 - Technology
620 - Engineering & allied operations
900 - History & geography
7
700 - The arts; fine & decorative arts
6
000 - Computer science, information & general works
3
551 - Geology, hydrology & meteorology
3
330 - Economics
2
363 - Other social problems & services
2
800 - Literature & rhetoric
2
170 - Ethics
1
320 - Political science
1
370 - Education
1
380 - Commerce, communications & transportation
1
581 - Specific topics in natural history
1
610 - Medicine & health
1