Classification
330 - Economics
16
363 - Other social problems & services
15
628 - Sanitary & municipal engineering
15
333 - Economics of land & energy
8
551 - Geology, hydrology & meteorology
5
600 - Technology
5
621 - Applied physics
5
000 - Computer science, information & general works
4
344 - Labor, social, education & cultural law
4
660 - Chemical engineering
4
340 - Law
3
380 - Commerce, communications & transportation
3
581 - Specific topics in natural history
3
300 - Social sciences
2
576 - Genetics & evolution
2
580 - Plants (Botany)
2
620 - Engineering & allied operations
2
800 - Literature & rhetoric
2
900 - History & geography
2
320 - Political science
1
338 - Production
1
362 - Social welfare problems & services
1
410 - Linguistics
1
540 - Chemistry & allied sciences
1
546 - Inorganic chemistry
1
577 - Ecology
1
610 - Medicine & health
1
630 - Agriculture & related technologies
1
631 - Techniques, equipment & materials
1
657 - Accounting
1
658 - General management
1
668 - Technology of other organic products
1
674 - Lumber processing, wood products & cork
1
677 - Textiles
1
700 - The arts; fine & decorative arts
1
720 - Architecture
1