What Do Farmers Financially Lose if they Fail to use Improved Seeds? Some Econometric Results for Wheat and Implications for Agricultural Extension Policy in Ethiopia. Ethiopian Journal of Economics, [S. l.], v. 12, n. 2, p. 60–81, 2006. Disponível em: http://ethiopianjournalofeconomics.org/index.php/EJE/article/view/367.. Acesso em: 18 apr. 2026.