Araújo, Paulo Graça, Gelio Nogueira Pizelli, Mauro Ribeiro de Carvalho, Osvaldo de Almeida Resende, and Dirce P. P. de Souza Britto. 2014. “Influence of Estrogen in Fertility of “problem" Cows (repeat-Breeding)”. Pesquisa Agropecuaria Brasileira 6 (1): 131-35. https://doi.org/10.1590/S1678-3921.pab1971.v6.17746.