13. Guillemot D, Carbon C, Balkan B et al : Low dosage and long treatment duration of beta-lactam : risk factor for carriage of penicillin-resisiant Streptococcus pneumonies.
13. Guillemot D, Carbon C, Balkan B et al: Low dosage and long treatment duration of beta-lactam: risk factor for carriage of penicillin-resisiant Streptococcus pneumonies.