Constable, P. D., J. C. Huhn, D. E. Morin, and D. R. Nelson. 1999. “Atresia Coli in Calves: Etiopathogenesis and Surgical Management”. The Bovine Practitioner 33 (1):70-73. https://doi.org/10.21423/bovine-vol33no1p70-73.