Caldas, José Vaz, e João Rebelo. «Technical Efficiency and Productivity Growth in the Farming System of the Douro Region: A Stochastic Frontier Approach». Douro : Estudos & Documentos, no. 15 (Novembro 4, 2022). Acedido Julho 30, 2025. http://84.247.136.72/ojsletrasX/index.php/dou/article/view/12642.