Nordic Hydrological Conference, 1998 (pp. 484–490)
or go to the pdf (or right click the latter and 'Save Link As ...').

Gumbricht, T., Maxe, L., & Johansson, P.-O. (1998). Rule based map generalisation for classification of groundwater vulnerability. In J. Kajander (Ed.), Nordic Hydrological Conference (pp. 484–490). Helsinki: NHP-Report No. 44.

Abstract