1. Moore, J. G., Englert, jun., E., and Brown, H., Clin. Res., 9, 64 (1961).
2. Makhlouf, G. M., Moore, E. W., and Blum, A. L., Gastroenterology, 55, 457 (1968).
3. Halberg, F., Engle, R., Treloar, A., and Gully, R., AMA Arch. Neurol. Psychiat., 69, 462 (1953).
4. Levin, E., Kirsner, J. G., and Palmer, W. L., Rev. Gastroenterol., 19, 226 (1952).
5. Mills, J. N., Physiol. Rev., 46, 129 (1966).