1. KWR Water Research Institute , Groningenhaven 7 , P.O. Box 1072, Nieuwegein 3430 BB, The Netherlands
2. Rathenau Instituut , PO Box 95366, Den Haag 2509 CJ, The Netherlands
3. Leiden University, Centre for Science and Technology Studies (CWTS) , P.O. Box 905 2300, AX Leiden, The Netherlands