Delgado, Darly Mildred, Diego Fernando Girón Timaná, Gabriel Elías Chanchí, and Katerine Márceles Villalba. 2019. “Estimate of the Satisfaction Attribute in User Tests from Facial Expression Analysis”. Revista Ingenierías Universidad De Medellín 19 (36):13-28. https://doi.org/10.22395/rium.v19n36a1.