Use of Placebo Surgery in Controlled Trials of a Cellular-Based Therapy for Parkinson's Disease
NEJM 341:988-992, Freeman,T.B.,et al, 1999
Bilateral Fetal Mesencephalic Grafting in Two Patients with Parkinsonism Induced by MPTP
NEJM 327:1556-1563, 15891992., Widner,H.,et al, 1992