Moraes, A. P. P., S. M. Barreto, V. M. A. Passos, P. S. Golino, J. A. Costa, and M. X. Vasconcelos. “Incidence and Main Causes of Severe Maternal Morbidity in São Luís, Maranhão, Brazil: A Longitudinal Study”. São Paulo Medical Journal, vol. 129, no. 3, May 2011, pp. 146-52, https://periodicosapm.emnuvens.com.br/spmj/article/view/1588.