RT Journal Article SR Electronic T1 Does a patient with a thunderclap headache need a lumbar puncture? JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 555 OP 556 DO 10.1503/cmaj.110517 VO 184 IS 5 A1 Fine, Ben A1 Singh, Navneet A1 Aviv, Richard A1 Macdonald, R. Loch YR 2012 UL http://www.cmaj.ca/content/184/5/555.abstract