1. Albert HM, Bryant LR, Schechter FG (1977) Seven year experience with mounted porcine valves. Ann Surg 185:717
2. Al-Janabi N, Gonzalez-Lavin L, Neirotti R, Ross, DN (1972) Viability of fresh aortic valve homo-grafts: A quantitative assessment. Thorax 27:83
3. Anderson ET, Hancock EW (1976) Long-term follow-up of aortic valve replacement with fresh aortic homograft. J Thorac Cardiovasc Surg 72:151
4. Angell WW (1976) Long-term results of tissue grafts for mitral replacement. The mitral valve (Kalmanson D, ed). Edward Arnold Ltd, London, p 481
5. Angell WW (1979) A nine year experience with the Angell-Shiley xenograft and a comparative literature review of the porcine bioprosthesis versus the mechanical prosthesis. Bioprosthetic cardiac valves (Sebening F, Klövekorn WP, Meisner H, Struck E, eds), Deutsches Herzzentrum München, p. 81