Safety and patients’ satisfaction of transcutaneous supraorbital neurostimulation (tSNS) with the Cefaly(R) device in headache treatment: a survey of 2,313 headache sufferers in the general population - Magis, D; Sava, S; d’Elia, TS; Baschi, R; Schoenen, J (J Headache Pain, 2013)