Classification
140 - Specific philosophical schools
2
330 - Economics
333 - Economics of land & energy
2
380 - Commerce, communications & transportation
600 - Technology
630 - Agriculture & related technologies
658 - General management
000 - Computer science, information & general works
1
363 - Other social problems & services
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1
620 - Engineering & allied operations
1