1. Postoperative pain;Bonica,1990
2. The influence of continuous passive motion on the results of total knee arthroplasty;Colwell;Clin Orthop Relat Res,1992
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4. Postcesarean epidural morphine: a dose–response study;Palmer;Anesth Analg,2000
5. Epidural morphine for postoperative pain: experience with 1085 patients;Stenseth;Acta Anaesthesiol Scand,1985