Classification
500 - Natural sciences & mathematics
363 - Other social problems & services
2
303 - Social processes
1
327 - International relations
1
330 - Economics
1
380 - Commerce, communications & transportation
1
540 - Chemistry & allied sciences
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1
630 - Agriculture & related technologies
1
700 - The arts; fine & decorative arts
1