D’Ambrosio, F., M. Del Grosso, R. Camilli, L. Ingrosso, M. G. Caporali, F. D’Ancona, and A. Pantosti. “Surveillance of Invasive Diseases Caused by Streptococcus Pneumoniae in Italy: Evolution of Serotypes and Antibiotic Resistance in Different Age Groups before and After Implementation of PCV7”. Microbiologia Medica, vol. 28, no. 1, Apr. 2013, doi:10.4081/mm.2013.2275.