@PROCEEDINGS {WINCH:1977a, title = {Review of production and trade of rice, maize, cassava, yam and sweet potatoes in selected countries of tropical Africa}, author = {Winch, F. E. and Kivunja, C. D. }, booktitle = {Papers presented for the tecnical advisory committee mission to IITA}, year = {1977}, publisher = {IITA, Ibadan}, note = {RTB; Root and Tuber.; October 1977}, }