Classification
380 - Commerce, communications & transportation
620 - Engineering & allied operations
600 - Technology
17
900 - History & geography
15
700 - The arts; fine & decorative arts
13
333 - Economics of land & energy
8
363 - Other social problems & services
8
576 - Genetics & evolution
6
140 - Specific philosophical schools
4
340 - Law
4
610 - Medicine & health
4
580 - Plants (Botany)
3
630 - Agriculture & related technologies
3
720 - Architecture
3
170 - Ethics
2
300 - Social sciences
2
320 - Political science
2
500 - Natural sciences & mathematics
2
550 - Earth sciences
2
800 - Literature & rhetoric
2
330 - Economics
1
370 - Education
1
400 - Language
1
530 - Physics
1
540 - Chemistry & allied sciences
1
551 - Geology, hydrology & meteorology
1
581 - Specific topics in natural history
1