@BOOKLET {DOUTHWAITE:2003b, title = {An impact assessment of IITA's benchmark area approach}, author = {Douthwaite, B. and Baker, D. and Weise, S. and Gockowski, J. and Manyong, V. and Keatinge, J. }, year = {2003}, address = {Ibadan, Nigeria}, howpublished = {Impact series}, note = {30p.; Impact series}, }