?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Niggli%2C+Urs&rft.aulast=Niggli&rft.aufirst=Urs&rft.date=2002&rft.title=The+contribution+of+research+to+the+development+of+organic+farming+in+Europe&rft.genre=proceeding