Raja Srinivasa N, Meyer Richard A, Campbell James N
Department of Anesthesiology / Critical Care Medicine The Johns Hopkins University School of Medicine Baltimore, MD 21287-5354, USA Department of Neurosurgery The Johns Hopkins University School of Medicine Baltimore, MD 21287-5354, USA.
Pain. 1993 Sep;54(3):361-362. doi: 10.1016/0304-3959(93)90039-R.