Classification
720 - Architecture
700 - The arts; fine & decorative arts
4
140 - Specific philosophical schools
3
300 - Social sciences
2
333 - Economics of land & energy
2
380 - Commerce, communications & transportation
2
900 - History & geography
2
200 - Religion
1
320 - Political science
1
363 - Other social problems & services
1
370 - Education
1
400 - Language
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1
600 - Technology
1
620 - Engineering & allied operations
1