Mordin M, Anastassopoulos K, van Breda A, Vallow S, Zhang M, Gargiulo K, Hewitt D, Olson W, Sikirica V. Clinical staff resource use with intravenous patient-controlled analgesia in acute postoperative pain management: results from a multicenter, prospective, observational study. J Perianesth Nurs. 2007 Aug 1;22(4):243-55.
Phillips C, White RP, Shugars DA, Zhou X. Risk factors associated with prolonged recovery and delayed healing after third molar surgery. J Oral Maxillofac Surg. 2003 Dec 1;61(12):1436-48.