1. Policy Document on Nature Development; an exploratory study;Baerselman,1989
2. Systematically in search of sustainable development;Brink,1989
3. Ecological impact assessment on coastal waters;Ministry of Transport an Public Works,1990
4. Third National policy document on watermanagement, A time for action;Ministry of Transport an Public Works,1989
5. Address given by the Minister of Transport and Public Works at the opening of the Third North Sea Conference (‘Distress Signals’);Smit-Kroes,1989