Classification
333 - Economics of land & energy
2
363 - Other social problems & services
2
580 - Plants (Botany)
600 - Technology
620 - Engineering & allied operations
2
700 - The arts; fine & decorative arts
900 - History & geography
380 - Commerce, communications & transportation
1
400 - Language
1
500 - Natural sciences & mathematics
1
800 - Literature & rhetoric
1