@ARTICLE {ALENE:2007c, title = {Gains from high-yielding varieties with and without complementary technologies: the case of improved cowpea in northern Nigeria}, author = {Alene, A. and Manyong, V. }, journal = {Journal of Agricultural and Food Economics}, year = {2007}, volume = {2}, number = {1}, pages = {1--14}, note = {IITA Technologies}, }