Erikson , U. ., Hallén , A. ., Helmius , G. ., Nyström , S.-O. ., & Ruhn , G. . (1980). Coronary By-pass Operation—Graft and Left Ventricular Function. Upsala Journal of Medical Sciences, 85(1), 84–93. https://doi.org/10.3109/03009738009179175