Englyst HN, Trowell H, Southgate DA, Cummings JH: Dietary fiber and resistant starch. Am J Clin Nutr 46: 873-874, 1987.
Trowell H: Definition of dietary fiber and hypotheses that it is a protective factor in certain diseases. Am J Clin Nutr 29: 417-427, 1976.
Trowell H: Ischemic heart disease and dietary fiber. Am J Clin Nutr 25: 926-932, 1972.
Bircher J, Muller J, Guogenheim P, et al.: Treatment of chronic portal-systemic encephalopathy with lactulose. Lancet 23: 890-892, 1996.
Oku T, Nakamura S: Estimation of intestinal trehalase activity from a laxative threshold of trhalose and lactulose on healthy female subjects. Eur J Clin Nutr 54: 783-788, 2000.