RT Journal Article SR Electronic T1 Caudal levobupivacaine vs ropivacaine for postoperative analgesia in children: 33. JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP 69 OP 69 DO 10.1053/rapm-00115550-200309001-00121 VO 28 IS Suppl 1 A1 E Sfyra YR 2003 UL http://rapm.bmj.com/content/28/Suppl_1/69.2.abstract AB