D’Ambrosio, F., Del Grosso, M., Camilli, R., Ingrosso, L., Caporali, M. G., D’Ancona, F. and Pantosti, A. (2013) “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, 28(1). doi: 10.4081/mm.2013.2275.