Real-world treatment utilization and safety of onabotulinumtoxinA for chronic migraine from an observational study in the European union. (25th December 2016) - Matharu, Manjit; Pascual, Julio; Remahl, Ingela Nilsson; Straube, Andreas; Lum, Arlene; Davar, Gudarz; Odom, Dawn; Bennett, Lee; Proctor, Christina; Gutierrez, Lia; Andrews, Elizabeth; Johannes, Catherine