Bhatia Kailash P, Griggs Robert C, Ptáček Louis J
University Department of Clinical Neurology, Institute of Neurology, University College London, Queen Square, London, U.K.
Department of Neurology, University of Rochester School of Medicine, Rochester, New York, U.S.A.
Mov Disord. 2000 May;15(3):429-433. doi: 10.1002/1531-8257(200005)15:3<429::AID-MDS1001>3.0.CO;2-R.