?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Thorup-Kristensen%2C+Kristian&rft.aulast=Thorup-Kristensen&rft.aufirst=Kristian&rft.date=2008&rft.title=Resource+efficiency+of+organic+and+low+input+systems+in+comparison+to+intensive+agriculture&rft.genre=proceeding