1. Vennesland, B., and Westheimer, F. H., in “Mechanism of Enzyme Action”, edited by McElroy, W. D., and Glass, B., p. 357 (Johns Hopkins Univ. Press, 1954).
2. Nason, A., in “Inorganic Nitrogen Metabolism”, edited by McElroy, W. D., and Glass, B., p. 109 (Johns Hopkins Univ. Press, 1956).
3. Nicholas, D. J. D., and Stevens, H. M., ibid., p. 178.
4. Nicholas, D. J. D., and Scawin, J. H., Nature, 178, 1474 (1956).
5. Taniguchi, S., Sato, R., and Egami, F., in “Inorganic Nitrogen Metabolism”, edited by McElroy, W. D., and Glass, B., p. 87 (Johns Hopkins Univ. Press, 1956).