?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=S+M&rft.au=Kabululu%2C+S+M&rft.aulast=Kabululu&rft.atitle=Cowpea+Cultivar+Mixtures+for+Stable+and+Optimal+Leaf+and+Seed+Yields+in+a+Maize+Intercropping+System&rft.title=International+Journal+of+Vegetable+Science&rft.issn=1931-5279&rft.date=2013&rft.pages=1-32&rft.genre=article