Markedly different rates and resistance profiles exhibited by seven commonly used and newer beta-lactams on the selection of resistant variants of Enterobacter cloacae. - Chan, WC; Li, RC; Ling, JM; Cheng, AF; Schentag, JJ; Chan, W C; Li, R C; Ling, J M; Cheng, A F; Schentag, J J (Journal of Antimicrobial Chemotherapy (JAC), 1999)