REY, Luís Carlos. “ Nasopharyngeal Streptococcus Pneumoniae Isolated from Healthy and Pneumonia Children in Fortaleza, Brazil: Serogroups and Antibiotic Resistance ”. Revista Do Instituto De Medicina Tropical De São Paulo, vol. 42, no. 4, Aug. 2000, pp. 184-, https://revistas.usp.br/rimtsp/article/view/30446.