1. Cardiovascular problems after age 70;Boas;Geriatrics,1950
2. Total population studied, procedures employed and incidence of complications;Braunwald;Circulation,1968
3. Deaths related to cardiac catheterization;Braunwald;Circulation,1968
4. Mitral valve replacement with a discoid prosthesis;Cooley;Ann. Thorac. Surg.,1967
5. Retrograde left heart catheterization;Hildner;Amer. J. Cardiol.,1966