Acknowledgements
For all the help I received for this article I want to thank in alphabetical order: Luc Amkreutz, Fred Brounen, Guido Creemers, Izabel Devriendt, Erik Drenth, Rengert Elburg, Jan Hansen, Sönke Hartz, Leendert Louwe Kooijmans, Medy Oberendorff, Daan Raemaekers, Bart Vanmontfort, Huub Schmitz, Peter Schut, Jo Smeets and Milco Wansleeben. The English text was translated by Hetty Otten-Vogelaar.
Review data:
Submission: 11/1/2012
Revision: 11/3/2012
2nd submission: 1/5/2012