Classification
333 - Economics of land & energy
361 - Social problems & social welfare in general
380 - Commerce, communications & transportation
4
330 - Economics
3
000 - Computer science, information & general works
2
363 - Other social problems & services
2
576 - Genetics & evolution
2
600 - Technology
2
620 - Engineering & allied operations
2
630 - Agriculture & related technologies
2
700 - The arts; fine & decorative arts
2
900 - History & geography
2
300 - Social sciences
1
320 - Political science
1
340 - Law
1
400 - Language
1
500 - Natural sciences & mathematics
1
580 - Plants (Botany)
1
610 - Medicine & health
1