Idiopathic Hemiparetic Parkinsonism, A Syndrome Distinct from Idiopathic Parkinsonism
Lancet 339:149-150, DeKeyser,J.,et al, 1992
The Epidemiology of Parkinson's Disease, A Case-Control Study of Young-Onset and Old-Onset Patients
Arch Neurol 48:903-907, Stern,M.,et al, 1991