1. Allanby, K. D., and Campbell, M. (1949). Guy's Hosp. Rep., 98, 18.
2. Abrahams, D. G., and Wood, P. (1951). Brit. Heart J., 13, 519.
3. Traite des Cardiopathies Conge'ntiales;Balsac, H.de; Metianu, C.; Durand, M.; Dubost, Ch;Masson et Cie, Paris,1954
4. Baker, C. G., Brock, R. C., Campbell, M., and Suzman, S. (1949). Brit. Heart J., 11, 170.
5. Brock, R. C., and Campbell, M. (1950). Brit. Heart J., 12, 377.