M. A. S. Rua, C. R. Quirino, A. Bartholazzi Junior, W. H. O. Vega, M. A. P. Barreto, and R. Bastos, “Relationship of serum testosterone, sperm production, and testis traits with fertility of Mangalarga Marchador stallions”, Rev. colomb. cienc. pecu., vol. 31, no. 1, pp. 36–44, Mar. 2018.