American Journal of Physiology: Regulatory, Integrative & Comparative Physiology. Apr98, Vol. 43 Issue 4, pR912. 9p. 12 Black and White Photographs, 4 Charts, 4 Graphs.
American Journal of Physiology: Gastrointestinal & Liver Physiology. May97, Vol. 35 Issue 5, pG1100. 9p. 5 Black and White Photographs, 1 Chart, 14 Graphs.