Ebeling Barbier , C., Johansson , L., Lind , L., Ahlström , H., & Bjerner , T. (2011). Several sources of error in estimation of left ventricular mass with M-mode echocardiography in elderly subjects. Upsala Journal of Medical Sciences, 116(4), 258–264. https://doi.org/10.3109/03009734.2011.596586