1. Davis GK, Roberts HF (1959) Urea toxicity in cattle. Gainesville, FL, Agricultural Experiment Station, Bulletin 611.
2. Effect of orally administered urea on the ammonia and urea concentration in the blood of cattle and sheep, with observations on blood ammonia levels associated with symptoms of alkalosis;Dinning;Am J Physiol,1948
3. Nonprotein nitrogen-induced ammonia toxicosis and ammoniated feed toxicity syndrome;Haliburton;Vet Clin North Am Food Anim Pract,1989
4. Veterinary toxicology;Hatch,1977
5. Ammonia intoxication resulting from urea poisoning by ponies;Hintz;J Am Vet Med Assoc,1970