Fajardo Hoyos, C. L., Gómez Sánchez, A. M., & Sarmiento Castillo, J. I. (2018). Variables associated to sales income behavior in the main market squares of Popayán, Colombia. Semestre Económico, 21(49), 115-145. https://doi.org/10.22395/seec.v21n49a5