1. Weatherall, D. J., and Clegg, J. B., The Thalassemia Syndromes (Blackwell Scientific Publications, Oxford, 1972).
2. Nienhuis, A. W., and Anderson, W. F., J. clin. Invest., 50, 2458 (1971).
3. Benz, E. J., Jr., and Forget, B. G., J. clin. Invest., 50, 2755 (1971).
4. Dow, L. W., Terada, M., Natta, C., Metafora, S., Grossbard, E., Marks, P. A., and Bank, A., Nature new Biol., 243, 114 (1973).
5. Nienhuis, A. W., Canfield, P. H., and Anderson, W. F., J. clin. Invest., 52, 1735 (1973).