Classification
330 - Economics
581 - Specific topics in natural history
600 - Technology
4
700 - The arts; fine & decorative arts
363 - Other social problems & services
3
140 - Specific philosophical schools
2
333 - Economics of land & energy
2
380 - Commerce, communications & transportation
2
630 - Agriculture & related technologies
2
320 - Political science
1
340 - Law
1
350 - Public administration & military science
1
370 - Education
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1
612 - Human physiology
1
620 - Engineering & allied operations
1
900 - History & geography
1