Factors associated with relative rates of antimicrobial resistance among Streptococcus pneumoniae in the United States: results from the TRUST Surveillance Program (1998-2002) - Karlowsky,J.A.; Thornsberry,C.; Jones,M.E.; Evangelista,A.T.; Critchley,I.A.; Sahm,D.F. (Clin Infect Dis, 2003)