Classification
004 - Data processing & computer science
19
550 - Earth sciences
9
551 - Geology, hydrology & meteorology
8
526 - Mathematical geography
7
910 - Geography & travel
5
520 - Astronomy & allied sciences
4
005 - Computer programming, programs & data
3
304 - Factors affecting social behavior
3
629 - Other branches of engineering
3
333 - Economics of land & energy
2
523 - Specific celestial bodies & phenomena
2
621 - Applied physics
2
307 - Communities
1
330 - Economics
1
509 - Historical, geographic & persons treatment
1
539 - Modern physics
1
577 - Ecology
1