Mangiafico, Salvatore, et al. “Semi-Quantitative and Qualitative Evaluation of Pial Leptomeningeal Collateral Circulation in Acute Ischemic Stroke of the Anterior Circulation: The Careggi Collateral Score”. Italian Journal of Anatomy and Embryology, vol. 118, no. 3, Dec. 2013, pp. 277-8, https://oajournals.fupress.net/index.php/ijae/article/view/1174.