Classification
551 - Geology, hydrology & meteorology
27
330 - Economics
21
333 - Economics of land & energy
18
363 - Other social problems & services
18
320 - Political science
11
700 - The arts; fine & decorative arts
10
620 - Engineering & allied operations
9
577 - Ecology
8
600 - Technology
5
624 - Civil engineering
5
900 - History & geography
5
000 - Computer science, information & general works
3
581 - Specific topics in natural history
3
610 - Medicine & health
3
304 - Factors affecting social behavior
2
340 - Law
2
576 - Genetics & evolution
2
910 - Geography & travel
2
005 - Computer programming, programs & data
1
006 - Special computer methods
1
100 - Philosophy & psychology
1
140 - Specific philosophical schools
1
301 - Sociology & anthropology
1
344 - Labor, social, education & cultural law
1
360 - Social problems & services; associations
1
380 - Commerce, communications & transportation
1
500 - Natural sciences & mathematics
1
519 - Probabilities & applied mathematics
1
613 - Personal health & safety
1
621 - Applied physics
1
627 - Hydraulic engineering
1
629 - Other branches of engineering
1
630 - Agriculture & related technologies
1
631 - Techniques, equipment & materials
1
658 - General management
1
710 - Civic & landscape art
1
720 - Architecture
1
794 - Indoor games of skill
1
800 - Literature & rhetoric
1