1. Anonymous, 1976. Analyse Oosterschelde alternatieven [analyses alternative ways of closure Oosterscheldel. Rapport Rijkswaterstaat: 190 pp. (in Dutch).
2. Anomymous, 1985. Biological Research Ems-Dollard estuary. Rijk- swaterstaat communications no. 40/1985, Den Haag: 182 pp.
3. Anonymous, 1989. Water voor nu en later. Derde Nota Waterhuishouding, (water for today and in the future; third report on watermanagement). ‘s-Gravenhage: 297 pp. On Dutch).
4. Anonymous, 1991. Trendanalyse van zwevend stof gegevens van de Waddenzee over de periode 1973–1990 (trendanalyses suspended matter in the Wadden Sea, 1973–1990) Report T753 Waterloopkundig Laboratorium: 24 pp. and 40 figures (in Dutch).
5. Anonymous, 1996. Grevelingenmeer: uniek maar kwetsbaar. De ontwikkelingen in de periode 1990–1995 (Grevelingenmeer, unique but vulnerable; developments 1990–1995). Report RIKZ96.014. 101 pp. (in Dutch).