RT Journal Article SR Electronic T1 Diagnosing acute headache JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 108 OP 112 DO 10.7861/clinmedicine.4-2-108 VO 4 IS 2 A1 Richard Davenport YR 2004 UL http://www.rcpjournals.org/content/4/2/108.abstract AB