RT Journal Article SR Electronic T1 Double‐blind comparison of levodopa and procyclidine in parkinsonism, with illustrations of levodopa‐induced movement disorders JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 31 OP 35 DO 10.1212/WNL.20.12_Part_2.31 VO 20 IS 12 Part 2 A1 William H. Timberlake YR 1970 UL http://n.neurology.org/content/20/12_Part_2/31.abstract AB