1. TERROINE, E. F., MOUROT, G., L’allantoine et les corps puriques d l’urine des mammiferes proviennent-ils partiellement de la degradation des matieres protiques? [French].Bulletin Soc. Chim. Biol. 13 (1931) 94–109.
2. MORRIS, S., RAY, S. C., The fasting metabolism of ruminants, Biochem. J. 33 (1939) 1217–1230.
3. BLAXTER, K. L., MARTIN, A. K., The utilization of protein as a source of energy in fattening sheep, Br. J. Nutr. 16 (1962) 397–407.
4. ELLIOTT, R. C., TOPPS, J. H., Nitrogen metabolism of African cattle fed diets with an adequate energy, low protein content, Nature, Lond. 197 (1963) 668–670.
5. TOPPS, J. H., ELLIOTT, R. C., Relationships between concentrations of ruminal nucleic acid and excretion of purine derivative by sheep, Nature, Lond. 205 (1965) 498–499.