Classification
170 - Ethics
200 - Religion
320 - Political science
330 - Economics
140 - Specific philosophical schools
1
297 - Islam, Babism & Bahai Faith
1
333 - Economics of land & energy
1
363 - Other social problems & services
1
370 - Education
1
581 - Specific topics in natural history
1
600 - Technology
1
620 - Engineering & allied operations
1