1. Lohr, G. W., and Waller, H. S., Klin. Wochens., 37, 833 (1959).
2. Cutts, J. H., Cell Separation (Academic, New York and London, 1970).
3. Dacie, J. V., and Lewis, S. M., in Practical Haematology, fourth ed., 506 (Churchill, London, 1970).
4. Mycek, M. J., in Methods in Enzymology (edit, by Perlman, G. E., and Lorand, L.), 19, 285 (Academic, New York and London, 1970).