?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Van+Evert%2C+F+K&rft.aufirst=F+K&rft.aulast=Van+Evert&rft.issn=0002-1962+&rft.pages=325-331&rft.atitle=CropSyst%3A+a+collection+of+object-oriented+simulation+models+of+agricultural+systems&rft.volume=86&rft.issue=2&rft.title=Agronomy+Journal+&rft.date=1994&rft.genre=article