Classification
580 - Plants (Botany)
333 - Economics of land & energy
3
000 - Computer science, information & general works
2
363 - Other social problems & services
2
380 - Commerce, communications & transportation
2
576 - Genetics & evolution
2
581 - Specific topics in natural history
2
500 - Natural sciences & mathematics
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1
800 - Literature & rhetoric
1