?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Gray%2C+Douglas&rft.aulast=Gray&rft.aufirst=Douglas&rft.date=2002&rft.title=Can+parasitic+gastro-enteritis+be+used+as+an+indicator+of+welfare+in+organic+sheep%3F&rft.genre=proceeding