?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Casagrande%2C+Marion&rft.aulast=Casagrande&rft.aufirst=Marion&rft.date=2006&rft.title=Incidence+of+limiting+factors+on+organic+winter+wheat+performance&rft.genre=proceeding