Barrientos-Marin, Jorge, and Efraín Arango-Sánchez. “Engel Curves in Medellin’s Households 2012-2015”. Apuntes Del Cenes, vol. 38, no. 68, Aug. 2019, pp. 185-12, doi:10.19053/01203053.v38.n68.2019.8479.