Silva, A. E. D. F., Dode, M. A., Porto, J. A., & Abreu, U. G. P. (1991). Seasonal sexual activity of Nellore bulls and their cross-breed with Fleckvieh and Chianina: biometric testicular characteristics. Pesquisa Agropecuaria Brasileira, 26(10), 1745–1750. https://doi.org/10.1590/S1678-3921.pab1991.v26.3521