Almeida, José Wilson Rodrigues de, et al. “Stutly of the Indeterminate Form of Chagas’ Disease by Dinamic Electrocardiography”. Revista Do Instituto De Medicina Tropical De São Paulo, vol. 24, no. 4, Aug. 1982, pp. 222-8, https://revistas.usp.br/rimtsp/article/view/196762.