Efficacy and tolerability of amitriptylinoxide in the treatment of chronic tension-type headache: a multicentre controlled study - Pfaffenrath, V; Diener, HC; Isler, H; Meyer, C; Scholz, E; Taneri, Z; Wessely, P; Zaiser-Kaschel, H; Haase, W; Fischer, W (Cephalalgia, 1994)