Noronha, P. B., J. Pedutti Neto, and V. Borelli. “Morphological Aspects Study of Spermatic Cord in Pêga Donkey”. Brazilian Journal of Veterinary Research and Animal Science, vol. 38, no. 5, Jan. 2001, pp. 209-13, doi:10.1590/S1413-95962001000500002.