title: Biofeedback and relaxation training for chronic headache: a controlled comparison of booster treatments and regular contacts for long-term maintenance.
mesh_terms: D001676:Biofeedback, Psychology; D005500:Follow-Up Studies; D006261:Headache / Q000628:therapy*; D006801:Humans; D012064:Relaxation Therapy; D014653:Vascular Headaches / Q000628:therapy