Ruiz, Isabel. «About the theory and empirical analysis of “the persistence of profit”and its applicability to Colombia». Ecos de Economía: A Latin American Journal of Applied Economics 7, no. 16 (marzo 15, 2003): 65–76. Accedido noviembre 11, 2026. https://publicaciones.eafit.edu.co/index.php/ecos-economia/article/view/2000.