GAMMOH, D. T.; ELSHENNAWY, A. K.; DUCHARME, A. Implementing Six Sigma in a Distance Learning Application. International Journal of Online and Biomedical Engineering (iJOE), [S. l.], v. 5, n. 2, p. pp. 23–29, 2009. DOI: 10.3991/ijoe.v5i2.875. Disponível em: https://online-journals.org/index.php/i-joe/article/view/875. Acesso em: 11 aug. 2022.