Classification
333 - Economics of land & energy
540 - Chemistry & allied sciences
28
620 - Engineering & allied operations
27
600 - Technology
24
700 - The arts; fine & decorative arts
9
363 - Other social problems & services
8
330 - Economics
5
500 - Natural sciences & mathematics
5
000 - Computer science, information & general works
4
580 - Plants (Botany)
4
630 - Agriculture & related technologies
4
530 - Physics
3
610 - Medicine & health
3
300 - Social sciences
2
370 - Education
2
380 - Commerce, communications & transportation
2
551 - Geology, hydrology & meteorology
2
576 - Genetics & evolution
2
581 - Specific topics in natural history
2
900 - History & geography
2
100 - Philosophy & psychology
1
140 - Specific philosophical schools
1
301 - Sociology & anthropology
1
320 - Political science
1
338 - Production
1
340 - Law
1
720 - Architecture
1
800 - Literature & rhetoric
1