R. Amaral, B. L. Migueis Nunes, J. Maciel Claudio, and M. Fonseca Ferreira, “Monitoring of progesterone and estradiol fecal metabolites during estrous cycle in sows”, Pubvet, vol. 13, no. 02, Feb. 2019, doi: 10.31533/pubvet.v13n2a267.1-6.