@inbook{1131932536, author={Gerald W. Smetana}, editor={Bajwa, Zahid H. and Wootton, R. Joshua and Warfield, Carol A.}, title={Historical Features in Primary Headache Syndromes}, booktitle={Principles and Practice of Pain Medicine, 3e}, publisher={McGraw-Hill Education}, address={New York, NY}, year={2016}, url={neurology.mhmedical.com/content.aspx?aid=1131932536} }