Levin JH, Benavides J, Caddick C, Laurie K, Wilterdink J, Yaghi S, Silver B, Khan M. Transcranial Doppler Ultrasonography As a Non-Invasive Tool for Diagnosis and Monitoring of Reversible Cerebral Vasoconstriction Syndrome. R I Med J (2013). 2016 Sep 01; 99(9):38-41.