Classification
GTAK - Hydrogeology
11
GTA - Hydrology - general
7
GUAA - Geography - physical
4
GNA - Geology - soil sciences
3
GVA - Oceanography
3
LCP - Limnology
3
UPVF - Surface waters - streams, rivers, lakes
3
GAN - Geosciences - mathematical methods, computer applications
2
GBHC - Ocean floor - sediments, morphology
2
GMAB - Hydrogeochemistry
2
GTAP - Hydrological investigation methods
2
UPN - Water protection, water quality, clean water
2
URA - Soil chemistry
2
GCAA - Regional geology - Germany
1
GCAC - Regional geology - noneuropean countries
1
GUA - Geography - general
1
GXA - Polar research - general
1
GXAA - Polar research - arctic region
1
GXAB - Polar research - antarctic region
1
LCH - Ecology - methods
1
LCO - Hydrobiology
1
LCR - Ecology of microorganisms - land and water
1
UAN - Environment - mathematical methods, computer applications
1
UHN - Landscape ecology
1
UHP - Protection of nature and landscape
1
UPC - Water - general aspects
1
UPCE - Water chemistry
1
UPT - Water pollution control and measurement
1
UPVC - Groundwater
1