?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=G+V&rft.au=Subbarao%2C+G+V&rft.aulast=Subbarao&rft.atitle=Long-term+effects+of+tillage%2C+phosphorus+fertilization+and+crop+rotation+on+pearl+millet-cowpea+productivity+in+the+West-African+Sahel&rft.title=Experimental+Agriculture&rft.issn=1469-4441&rft.date=2000&rft.volume=36&rft.pages=243-264&rft.issue=2&rft.genre=article