Editorial. REVISTA DE INVESTIGACIÓN SIGMA, [S. l.], v. 6, n. 01, p. 5–8, 2019. DOI: 10.24133/sigma.v6i01.1320. Disponível em: https://journal.espe.edu.ec/ojs/index.php/Sigma/article/view/1320.. Acesso em: 17 may. 2024.