1. Gilbert, W. Nature, 271, 501 (1978).
2. Griffin, B. E., Fried, M. and Cowie, A. PNAS, 71, 2077 (1974).
3. Nomura, M. in Proceedings of the 10th FEBS Meeting Chapeville, F., Grunberg-Manago, M. (eds) North Holland/American Elsevier, New York, 233 (1975).
4. Nomura, M. Cell, 9, 633 (1976).
5. Sanger, F. et al. Nature, 265, 687 (1977).