1. Alagille, D., and Soulier, J. P. (1957). Rev. int. Hepar., 7, 1.
2. Blomback, B., and Blombick, M. (1957). Ark. Kemi, 10, 415.
3. Cole, P. G., Lathe, G. H., and Billing B. H. (1954). Biochem. J., 57, 514.
4. Jim, R. T. S. (1957). J. Lab. clin. Med., 50, 45.
5. Kowalski, E. (1960). Thromb. Diath. haemorrh. (Stuttg.), Suppl. 4, p. 211.