Barreto-Acevedo, Elliot, et al. “Efficacy and Safety of the Long-Term Vagus Nerve Stimulation: Preliminary Report in Adult Patients With Drug-Resistant Focal Epilepsy”. Revista De Neuro-Psiquiatria, vol. 82, no. 3, Oct. 2019, pp. 183-91, doi:10.20453/rnp.v82i3.3571.