@ARTICLE {MOYO:2007, title = {Challenges and opportunities for improvement in cassava and sweetpotato seed systems in Southern Africa}, author = {Moyo, C. and Mahungu, N. and Mkumbira, J. and Benesi, I. *}, journal = {Roots}, year = {2007}, volume = {10}, number = {2}, pages = {17--20}, note = {RTB; Root and Tuber}, }