1. Umweltprobleme der Nordsee,1980
2. Ministerial Declaration,1987
3. The Water Framework directive: Directive 2000/60/EC of the European Parliament and of the Council Establishing a Framework for the Community Action in the Field of Water Policy,2000
4. OSPAR List of Substances of Possible Concern,2002
5. The Attitudes of European Citizens towards Environment,2005