Candini PH, Moretti A de S, Zanella EL, Silveira PRS da, Viana CHC, Santos I. Single or double artificial insemination in fixed time in sows with ovulation induced by Luteinizing Hormon. Braz. J. Vet. Res. Anim. Sci. 2004;41(2):124-130. doi:10.1590/S1413-95962004000200008