Features and hospital outcomes of coronary artery bypass grafting in patients with calcification of target coronary arteries oleh R. S. Akchurin, A. A. Shiryaev, V. P. Vasiliev, D. M. Galyautdinov, E. E. Vlasova, I. S. Fedotenkov, S. K. Kurbanov, G. B. Mayorov