Classification
000 - Computer science, information & general works
330 - Economics
600 - Technology
140 - Specific philosophical schools
2
333 - Economics of land & energy
2
620 - Engineering & allied operations
2
630 - Agriculture & related technologies
2
380 - Commerce, communications & transportation
1
551 - Geology, hydrology & meteorology
1
580 - Plants (Botany)
1