@INBOOK {ASIEDU:1998, title = {Genetic improvement}, author = {Asiedu, R. and Ng, S. Y. C. and Bai, K. V. and Ekanayake, I. J. and Wanyera, N. }, editor = {Orkwor, G. C. and Asiedu, R. and Ekanayake, I. J. }, year = {1998}, type = {Food yams: advances in research}, pages = {63--104}, publisher = {International Institite of Tropical Agriculture (IITA); NRCRI}, address = {Ibadan; Umudike, Nigeria}, }