M. Kurtz Filho, “Gestation length related to the age in Thoroughbred mares, to placenta’s and newborn foal’s weight and parturition time”, Braz. J. Vet. Res. Anim. Sci., vol. 34, no. 1, pp. 37–40, Feb. 1997, doi: 10.11606/issn.2318-3659.v34i1p37-40.