Bertan, Claudia Maria, et al. “Induction of Ovulation in Cows With Affinity Chromatography-Purified Human Chorionic Gonadotropin (hCG)”. Brazilian Journal of Veterinary Research and Animal Science, vol. 43, no. 3, June 2006, pp. 379-86, https://doi.org/10.11606/issn.1678-4456.bjvras.2006.26486.