Classification
630 - Agriculture & related technologies
20
330 - Economics
17
580 - Plants (Botany)
17
000 - Computer science, information & general works
15
600 - Technology
14
620 - Engineering & allied operations
13
363 - Other social problems & services
11
551 - Geology, hydrology & meteorology
11
610 - Medicine & health
11
700 - The arts; fine & decorative arts
11
900 - History & geography
8
320 - Political science
7
333 - Economics of land & energy
7
581 - Specific topics in natural history
4
658 - General management
4
300 - Social sciences
3
340 - Law
3
576 - Genetics & evolution
3
800 - Literature & rhetoric
3
500 - Natural sciences & mathematics
2
380 - Commerce, communications & transportation
1
400 - Language
1
530 - Physics
1
540 - Chemistry & allied sciences
1
550 - Earth sciences
1
631 - Techniques, equipment & materials
1