Nonmotor Fluctuations in Patients with Parkinson's Disease
Neurol 47:1180-1183, Hillen,M.E.&Sage,J.I., 1996
The Spectrum of Levodopa-Related Fluctuations in Parkinson's Disease
Neurol 43:1459-1464, Riley,D.E.&Lang,A.E., 1993
The Olfactory and Cognitive Deficits of Parkinson's Disease:Evidence for Independence
Ann Neurol 25:166-171, Doty,R.L.,et al, 1989