1. Dacie, J. V.: Practical haematology, 2nd ed. London: Churchill 1956.
2. Jones, N. F., R. W. Payne, R. D. Hyde, and T. M. L. Price: Lancet 1, 299 (1960).
3. Betre, K.: Erg. Inn. Med. Kinderheilk. NF 9, 437 ff. (1958).
4. Pearson, C. M., W. Beck, and W. H. Bland: Arch. intern. Med. 99, 376 (1957).
5. Martinek, R. G.: Proc. Ass. clin. Biochem. 3, 228 (1965).