HOLZHEY, D. M.; SHI, W.; RASTAN, A.; BORGER, M. A.; HÄNSIG, M.; MOHR, F. W. Transapical versus Conventional Aortic Valve Replacement—A Propensity-Matched Comparison. The Heart Surgery Forum, v. 15, n. 1, p. E4-E8, 23 Feb. 2012.