Classification
550 - Earth sciences
16
551 - Geology, hydrology & meteorology
13
560 - Paleontology; paleozoology
10
910 - Geography & travel
7
333 - Economics of land & energy
4
624 - Civil engineering
4
523 - Specific celestial bodies & phenomena
1
526 - Mathematical geography
1
571 - Physiology & related subjects
1
578 - Natural history of organisms
1