Tal  Raz, Hunter, Barbara , Carley, Sylvia , and Card, Claire . 2009. ?Reproductive Performance Of Donor Mares Subsequent To Efsh Treatment In Early Vernal Transition: Comparison Between The First, Second, And Mid-Season Estrous Cycles Of The Breeding Season?. Anim Reprod Sci, 116, 1-2, Pp. 107-18. doi:10.1016/j.anireprosci.2008.12.008.