Norg Roelf J C, El Bakkali Nadia, Portegijs Piet J M, Knottnerus J André, van Schayck C P
Department of General Practice Care, Public Health Research Institute, Universiteit Maastricht, Maastricht, the Netherlands.
Eur J Gen Pract. 2007;13(3):164-6. doi: 10.1080/13814780701474179.