Sossa Azuela, J. H., F. Arce-Vega, W. Gómez-Flores, and L. Lira. “Training an Artificial Neural Network to Compute the Euler Number of a 2-D Binary Image Based on Vertex Chain Codification”. International Journal of Combinatorial Optimization Problems and Informatics, vol. 13, no. 1, Sept. 2021, pp. 4-17, https://ijcopi.org/ojs/article/view/261.