Westafer LM, Milne WK, Carpenter CR. Hot Off the Press: An Observational Study of 2,248 Patients Presenting with Headache, Suggestive of Subarachnoid Hemorrhage, That Received a Lumbar Puncture Following a Normal Computed Tomography of the Head. Acad Emerg Med. 2016 06; 23(6):750-2.