Increased Risk of Hemorrhagic Stroke in Patients with Migraine: A Population-Based Cohort Study. - Cheng-Ya Kuo; Ming-Fang Yen; Li-Sheng Chen; Ching-Yuan Fann; Yueh-Hsia Chiu; Hsiu-Hsi Chen; Shin-Liang Pan (PLoS ONE, 2013)