Farrar John T
Department of Biostatistics and Epidemiology, Anesthesiology, and Neurology, University of Pennsylvania School of Medicine, 423 Guardian Drive, Room 816, Philadelphia, PA 19104, USA.
Pain. 2010 May;149(2):163-164. doi: 10.1016/j.pain.2010.03.013. Epub 2010 Mar 26.