Disorders of the Nervous System Caused by Drugs, Toxins, and Chemical Agents, Opiates and Synthetic Analgesic Drugs
Adams & Victors Principles of Neurology Chp 43, pg 1201, Ropper, A.H.,et al, 2014
Cortical Evoked Responses & Transcutaneous Electrotherapy
Neurol 30:663-665, Salar,G.,et al, 1980