Llerena, W. F. T., E. Santamaría-Freire, and M. D. G. Guevara. “Informal Trade As a Predominant Factor in the Local Economy of Ambato, Ecuador”. Journal of Applied Business and Economics, vol. 21, no. 5, Sept. 2019, https://articlearchives.co/index.php/JABE/article/view/862.