Welch William C
Department of Neurosurgery, University of Pennsylvania, Washington West Bldg. of the Pennsylvania Hospital, 235 South 8th St, Philadelphia, PA, 19106, USA,
Eur Spine J. 2013 Sep;22(9):2055-6. doi: 10.1007/s00586-013-2820-7. Epub 2013 Jun 1.