Degenerative Diseases of the Nervous System, Parkinson Disease
Adams & Victors Principles of Neurology, Chp 39, pg 1082, Ropper, A.H.,et al, 2014
Parkinson's Disease
In Handbk of Clinical Neurology, Vinken, P. J. & Bruyn, G. W. , Ed, North-Holland Publ Co, Amsterdam, 6:173, 1968. Selby, G., 1968