Chiricolo, Antonio, and Leonard Y Lee. “Mitral Valve Repair for Functional Mitral Regurgitation-Description of A New Technique and Classification System”. Cardiology and Cardiovascular Medicine, vol. 1, no. 6, Nov. 2017, pp. 230-5, http://www.fortunejournals.org/ojs/index.php/ccm/article/view/15441.