?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Clarke%2C+Dr+Sarah+M.&rft.aulast=Clarke&rft.aufirst=Sarah+M.&rft.date=2006&rft.title=A+participatory+approach+to+variety+trials+for+organic+systems&rft.genre=proceeding