MIRANDA-FILHO, Demócrito B., et al. “ Identification of Risk Factors for Death from Tetanus in Pernambuco, Brazil: A Case-Control Study ”. Revista Do Instituto De Medicina Tropical De São Paulo, vol. 42, no. 6, Dec. 2000, pp. 333-9, https://www.revistas.usp.br/rimtsp/article/view/30468.