Classification
500 - Natural sciences & mathematics
630 - Agriculture & related technologies
38
600 - Technology
25
620 - Engineering & allied operations
25
580 - Plants (Botany)
20
581 - Specific topics in natural history
18
330 - Economics
15
363 - Other social problems & services
13
700 - The arts; fine & decorative arts
12
333 - Economics of land & energy
10
000 - Computer science, information & general works
9
320 - Political science
9
551 - Geology, hydrology & meteorology
9
610 - Medicine & health
8
576 - Genetics & evolution
7
380 - Commerce, communications & transportation
6
140 - Specific philosophical schools
5
540 - Chemistry & allied sciences
4
300 - Social sciences
3
340 - Law
3
800 - Literature & rhetoric
3
900 - History & geography
3
338 - Production
2
370 - Education
2
530 - Physics
2
304 - Factors affecting social behavior
1
361 - Social problems & social welfare in general
1
400 - Language
1
510 - Mathematics
1
577 - Ecology
1
612 - Human physiology
1
621 - Applied physics
1
632 - Plant injuries, diseases & pests
1
657 - Accounting
1
720 - Architecture
1