RT Journal Article SR Electronic T1 Smith and Kocen reply JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 687 OP 687 DO 10.1136/jnnp.52.5.687 VO 52 IS 5 YR 1989 UL http://jnnp.bmj.com/content/52/5/687.1.abstract AB