Sakabe, F. F., D. I. Sakabe, G. A. Gonçalves, and P. B. dos Santos. “Manipulation Based on Fryette’s Laws Increases Heart Rate Variability and Muscle Flexibility in Subjects With Headache”. Manual Therapy, Posturology & Rehabilitation Journal, Oct. 2018, pp. 1-6, doi:10.17784/mtprehabjournal.2018.16.600.