J. M. de Almeida, R. M. B. Santos, M. A. Miglino, and L. de Morais-Pinto, “Morphology of the ‘funiculus umbilicalis’ in wooless mongrel sheep (Ovis aries, L. 1758)”, Braz. J. Vet. Res. Anim. Sci., vol. 37, no. 3, pp. 189–193, Jan. 2000, doi: 10.1590/S1413-95962000000300003.