Llinás Solano, H., M. Arteta Charris, and J. Tilano Hernández. “The Regression Logistics Model in Case the Response Variable Assumes One of Three Levels: Estimations, Proof of Hypothesis and Model Selection”. Revista De Matemática: Teoría Y Aplicaciones, vol. 23, no. 1, Apr. 2017, pp. 173-97, doi:10.15517/rmta.v23i1.22442.