Rietveld, J.C.

Rietveld, J.C., 1987. An overdue plea for support for local, regional and international professional associations : paper presented at the symposium "Opening up new horizons", 15 December 1987 organised by the Watertransportmij Rijn-Kennemerland WRK, S.l.: Watertransportmatschappij Rijn-Kennemerland WRK.