?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Salonen&rft.aufirst=Jukka&rft.au=Salonen%2C+Jukka&rft.date=2009&rft.title=Repeated+surveys+in+Finland+follow+the+changes+of+weed+flora+in+spring+cereal+fields&rft.genre=proceeding