Classification
330 - Economics
700 - The arts; fine & decorative arts
320 - Political science
5
600 - Technology
4
900 - History & geography
4
333 - Economics of land & energy
2
100 - Philosophy & psychology
1
140 - Specific philosophical schools
1
200 - Religion
1
304 - Factors affecting social behavior
1
340 - Law
1
363 - Other social problems & services
1
370 - Education
1
380 - Commerce, communications & transportation
1
500 - Natural sciences & mathematics
1
551 - Geology, hydrology & meteorology
1
576 - Genetics & evolution
1
620 - Engineering & allied operations
1
630 - Agriculture & related technologies
1