A. E. D. F. Silva, M. A. Dode, J. A. Porto, and U. G. P. Abreu, “Seasonal sexual activity of Nellore bulls and their cross-breed with Fleckvieh and Chianina: biometric testicular characteristics”, PAB, vol. 26, no. 10, pp. 1745–1750, Oct. 1991, doi: 10.1590/S1678-3921.pab1991.v26.3521.