Silva, Antônio Emidio Dias Feliciano, Margot Alves Dode, João Abela Porto, and Urbano Gomes P. Abreu. 1991. “Seasonal Sexual Activity of Nellore Breed Bulls and Their Crosses With Fleckvieh and Chianina: Spermatic Characteristics”. Pesquisa Agropecuaria Brasileira 26 (10):1751-60. https://doi.org/10.1590/S1678-3921.pab1991.v26.3522.