@INBOOK {JOHNSON:2005, title = {The impact of IARC genetic improvement programmes on cassava}, author = {Johnson, N. and Manyong, V. and Pachico, D. }, editor = {Evenson, R. and Gollin, D. }, year = {2003}, type = {Crop variety improvement and its effect on productivity: the impact of international agricultural research}, pages = {337--355}, publisher = {CABI}, address = {Wallingford, UK}, note = {RTB; Root and Tuber; Cassava}, }