?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Kijlstra%2C+Prof.+Dr.+Aize&rft.aulast=Kijlstra&rft.aufirst=Aize&rft.date=2006&rft.title=Challenges+for+avoiding+and+handling+disease+problems+in+organic+herds&rft.genre=proceeding