@INPROCEEDINGS {NG: 1994a,
title = {Production and distribution of virus-free yam (Dioscorea rotundata Poir.)},
author = {Ng, S. Y. C. },
editor = {Ofori, F and Hahn, S. K. },
booktitle = {Tropical root crops in a developing economy: proceedings of the 9th Symposium of the International Society for Tropical Rooy Crops, 20-26 October 1991, Accra, Ghana},
year = {1994},
pages = {324--328},
publisher = {ISTRC; Government of Ghana; International Institute of Tropical Agriculture (IITA)},
address = {Accra, Ghana},
note = {RTB; Root and Tuber; Yam},
}