Sustainable integrated management of whiteflies as vectors of viruses of cassava and sweetpotato: situation analysis of three farmers groups in south eastern Nigeria - Okwusi, M.; Ogbe, F.; Nwauzor, E.C.; Asumugha, G.N.; Mbanasor, E.; Akinpelu, A.O.; Legg, James P.; Emehute, J.K. (2006)