G. A. González Vargas, “Income increase through management of the customer service level. A case of application”, Rev. DyC. EAFIT, vol. 42, no. 141, pp. 9–18, June 2012, Accessed: Nov. 11, 2026. Available: https://publicaciones.eafit.edu.co/index.php/revista-universidad-eafit/article/view/806