?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=M+R&rft.au=Rao%2C+M+R&rft.aulast=Rao&rft.atitle=Productivity+and+risk+evaluation+in+contrasting+intercropping+systems&rft.title=Field+Crops+Research&rft.issn=0378-4290&rft.date=1990&rft.volume=23&rft.pages=279-293&rft.issue=3-4&rft.genre=article