Valentim, Renato, et al. “Testicular Biometry of Nellore (Bos Taurus Indicus) and Crossbred Bulls (Bos Taurus Indicus X Bos Taurus Taurus) at 20 and 24 Months of Age”. Brazilian Journal of Veterinary Research and Animal Science, vol. 39, no. 3, Jan. 2002, pp. 113-20, https://doi.org/10.1590/S1413-95962002000300001.