RT Journal Article SR Electronic T1 Amyotrophic Lateral Sclerosis JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 191 OP 191 DO 10.1136/jnnp.44.2.191-a VO 44 IS 2 A1 CD Marsden YR 1981 UL http://jnnp.bmj.com/content/44/2/191.2.abstract AB