Yahiaoui, R.Y., Heijer, C.D.J. den, Bijnen, E.M.E. van, Paget, W.J., Pringle, M., Goossen, H., Bruggeman, C.A., Schellevis, F.G., Stobberingh, E.E. Prevalence and antibiotic resistance of commensal Streptococcus pneumoniae in nine European countries. Future Microbiology: 2016, 11(6), 737-744