title: Four process studies in the behavioral treatment of chronic headache.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001521:Behavior Therapy / Q000379:methods*; D001676:Biofeedback, Psychology; D002908:Chronic Disease; D005260:Female; D006261:Headache / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011369:Professional-Patient Relations