Opstelten Wim, van Wijck Albert J M, Stolker Robert J
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85060, 3500 AB Utrecht, The Netherlands Department of Anesthesiology, University Medical Center Utrecht, Utrecht, The Netherlands Department of Anesthesiology, Catharina Hospital, Eindhoven, The Netherlands.
Pain. 2004 Feb;107(3):202-206. doi: 10.1016/j.pain.2003.10.021.