Kyriakakis, C.G., R. Brauns, B.J. Barnard, A.F. Doubell, and P.G. Herbst. “Answer to Echocardiography Quiz”. SA Heart Journal 8, no. 4 (April 5, 2017): 272–275. Accessed October 8, 2025. https://www.journals.ac.za/SAHJ/article/view/1890.