Normas Editoriales. REVISTA DE INVESTIGACIÓN SIGMA, [S. l.], v. 6, n. 02, 2019. DOI: 10.24133/sigma.v6i2.1677. Disponível em: https://journal.espe.edu.ec/ojs/index.php/Sigma/article/view/1677. Acesso em: 4 apr. 2025.