1. Department of Spatial Planning and Environment, University of Groningen, Landleven 1, 9747 AD Groningen, The Netherlands, w.g.z.tan@rug.nl
2. Department of Human Geography, Planning and International Development, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV, Amsterdam, the Netherlands, L.Bertolini@uva.nl
3. Department of Human Geography, Planning and International Development, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV, Amsterdam, the Netherlands, L.B.Janssen-Jansen@uva.nl