Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A revolutionary guide and reference to the ultimate answer with respect to the common problem of the headache

Relief From Headache by clinician and medical research investigator Donald I. Peterson (a retired Professor of Neurology and Associate Professor of Pharmacology at Loma Linda University School of Medicine, Loma Linda, California) is a revolutionary guide and reference to the ultimate answer with respect to the common problem of the headache. As the compiled results of Peterson's many knowledgeable years of study, Relief From Headache expertly explores the causes of what might relieve a headaches persistence and striking pain. Relief From Headache is very highly recommended to all readers who suffer from frequent headaches for its educational, informative and "reader friendly" content.