Classification
UPC - Water - general aspects
4
UAN - Environment - mathematical methods, computer applications
2
UPK - Water resources, water supply
2
UPN - Water protection, water quality, clean water
2
UPP - Water pollution
2
UPT - Water pollution control and measurement
2
UPVC - Groundwater
2
UPVF - Surface waters - streams, rivers, lakes
2
GKA - Geophysics - general
1
GTAK - Hydrogeology
1