1. Groundwater Nitrate Contamination Risk Assessment: A Comparison of Parametric Systems and Simulation Modelling
2. Guidelines for Drinking Water Quality. 1. Recommendations,1993
3. Agriculture, Fertilizers and The Environment;Laegreid,1999
4. European Economic Community, Council Directive concerning the protection ofwaters against pollution caused by nitrates from agricultural sources. Official Journal of the European Communities, 1991/676/EEC.
5. European Community, 120 Final Report from the Commission to the council and the European Parliament. On implementation of Council Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources for the period 2000–2003 {SEC(2007)339}, COM(2007).