@INBOOK {SMITH:1993a, title = {The role of technology in agricultural intensification: the evolution of maize production in the northern Guinea savannah of Nigeria}, author = {Smith, J. and Barau, A. D. and Goldman, A. and Mareck, J. H. }, editor = {Dvorak, K. A. }, year = {1993}, type = {Social science research for agricultural technology development: spatial and temporal dimensions}, pages = {144--166}, publisher = {CAB International}, address = {Wallingford, Oxon, UK}, }