Armstrong , C. L., D. F. Wolfe, J. H. Koziol, and R. L. Carson. “Preputial Stoma: A Novel Surgical Approach For Semen Collection In Bulls With Phimosis Due To Preputial Stenosis; Three Cases (2007–2014)”. Clinical Theriogenology, vol. 7, no. 4, Dec. 2015, pp. 419-23, https://clinicaltheriogenology.net/index.php/CT/article/view/10100.