@INBOOK {NG:1999b, title = {Biotechnology in germplasm management of cassava and yams: in plant conservation biotechnology}, author = {Ng, S. Y. C. and Mantell, S. H. and Ng, N. Q. }, editor = {Benson, E. E. }, year = {1999}, type = {Plant conservation biotechnology}, pages = {179--209}, publisher = {Taylor and Francis}, address = {London, UK}, note = {RTB; Root and Tuber.; IITA Technologies}, }