?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Askegaard%2C+Margrethe&rft.aulast=Askegaard&rft.aufirst=Margrethe&rft.date=2005&rft.title=Long-term+organic+crop+rotation+experiments+for+cereal+production+%C3%A2%C2%80%C2%93+yield+development+and+dynamics&rft.genre=proceeding