CANTILLO-GARCIA, Victor; GUZMAN, Luis A.  and  ARELLANA, Julian. Socioeconomic strata as proxy variable for household income in transportation research. Evaluation for Bogotá, Medellín, Cali and Barranquilla. Dyna rev.fac.nac.minas [online]. 2019, vol.86, n.211, pp.258-267. ISSN 0012-7353.