Estimation of Farm Level Technical Efficiency and its Determinants among Male and Female Sweet Potato Farmers in Imo State, Nigeria. Ethiopian Journal of Economics, [S. l.], v. 20, n. 1, p. 99–112, 2012. Disponível em: http://ethiopianjournalofeconomics.org/index.php/EJE/article/view/110.. Acesso em: 18 apr. 2026.