?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Walkenhorst%2C+Michael&rft.aulast=Walkenhorst&rft.aufirst=Michael&rft.date=2006&rft.title=Focussing+on+health+promotion+on+organic+farming+in+practice+%C3%A2%C2%80%C2%93+the+example+of+the+Swiss+pro-q+project+&rft.genre=proceeding