?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Olesen%2C+J%C3%83%C2%B8rgen+E.&rft.aulast=Olesen&rft.aufirst=J%C3%83%C2%B8rgen+E.&rft.date=2004&rft.title=Nitrate+leaching+from+arable+crop+rotations+in+organic+farming&rft.genre=proceeding