Walker Ruth H, Fink John K
Department of Neurology, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA; Mount Sinai School of Medicine, New York City, NY, USA.
Parkinsonism Relat Disord. 2013 Dec;19(12):1169-70. doi: 10.1016/j.parkreldis.2013.07.025. Epub 2013 Aug 20.