Classification
UPN - Water protection, water quality, clean water
4
UPP - Water pollution
3
UPVC - Groundwater
3
UPK - Water resources, water supply
2
UPT - Water pollution control and measurement
2
GTAK - Hydrogeology
1
UPA - Water - handbooks
1
UPTF - Organic pollutants in water
1
UPTN - Inorganic pollutants in water
1
URA - Soil chemistry
1
UVC - Environmental chemicals, hazardous materials - general aspects
1