1. Alférez, M. J. M., López Aliaga, I., Barrionuevo, M., Lisbona, F., Hartiti, S., Pallarés, I. and Campos, M.S. (1996): Internat. J. Vit. Nutr. Res., 66, 59–65.
2. American Institute of Nutrition (1977): J. Nutr., 107, 1340–1348.
3. Barton, J. C., Conrad, M. E. and Parmley, R. T. (1983): Gastroenterology, 84, 90–91.
4. Boza, J. and Sanz Sampelayo, M. R. (1997): An. Acad. Cienc. Veter. Andalucía Oriental, 10, 109–139.
5. Campos, M. S., López Aliaga, I., Barrionuevo, M., Lisbona, F. and Coves, F. (1989): J. Nutr. Sci. Vitaminol., 35, 511–521.