?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Hansen%2C+Sissel&rft.aulast=Hansen&rft.aufirst=Sissel&rft.date=2008&rft.title=A+discussion+of+norms+for+S+supply+in+organic+farming+based+on+content+in+forage+and+ruminant+performance+in+Norway&rft.genre=proceeding