Avendaño Cárdenas, David Bernardo, Mayra Alejandra Salto Simbaña, and Rómulo Astudillo. “Analysis of the Opacity Level of the Urban Bus Fleet of Cooperativa Uncometro S.A”. Revista Tecnológica - ESPOL 32, no. 2 (December 30, 2020): 89–94. Accessed November 2, 2025. https://rte.espol.edu.ec/index.php/tecnologica/article/view/716.