Classification
140 - Specific philosophical schools
320 - Political science
330 - Economics
333 - Economics of land & energy
1
336 - Public finance
1
361 - Social problems & social welfare in general
1
363 - Other social problems & services
380 - Commerce, communications & transportation
1
551 - Geology, hydrology & meteorology
1
580 - Plants (Botany)
1
600 - Technology
658 - General management
800 - Literature & rhetoric
1