RT Journal Article SR Electronic T1 Headache Classification and Epidemiology JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 108 OP 109 DO 10.1136/jnnp.59.1.108-b VO 59 IS 1 A1 R C Peatfield YR 1995 UL http://jnnp.bmj.com/content/59/1/108.3.abstract AB