@PROCEEDINGS {TERRY:1980b, title = {Increasing and stabilising cassava and sweet potato productivity by disease resistance and crop hygiene}, author = {Terry, E. R. and Hahn, S. K. }, booktitle = {Paper presented at the 1st East African Regional Root Crops Workshop, Kigali, Rwanda, 22-27 November, 1980}, year = {1980}, note = {RTB; Root and Tuber}, }