Editorial. REVISTA DE INVESTIGACIÓN SIGMA, [S. l.], v. 6, n. 02, p. 5, 2020. DOI: 10.24133/sigma.v6i2.1667. Disponível em: https://journal.espe.edu.ec/ojs/index.php/Sigma/article/view/1667.. Acesso em: 22 jul. 2024.