Gomes, Danilo C., et al. “Perforated Duodenal Ulcer Associated With Nonsteroidal Antiinflammatory Drug Administration in a Dairy Cow”. Brazilian Journal of Veterinary Pathology, vol. 1, no. 2, Nov. 2008, pp. 56-58, https://doi.org/10.24070/bjvp.1983-0246.001011.