The cassava food commodity market and trade network in Nigeria - Ezedinma, C.I.; Ojioko, I.A.; Okechukwu, R.U.; Lemchi, J.; Umar, A.M.; Sanni, Lateef O.; Akoroda, M.O.; Ogbe, F.; Okoro, E.; Tarawali, G.; Dixon, A. (2007)