Pérez de G., M.A. (1989) “Role of group A beta-hemolytic streptococcus in children with chronic recurrent tonsillopharyngitis”, Medicina UPB, 8(2), pp. 141–149. Available at: https://revistas.upb.edu.co/index.php/medicina/article/view/5654 (Accessed: 25 July 2026).