Luiz, Carlos Rosemberg, et al. “Comparative Study of the Irrigation of the Mammary Papilla in Mongrel Dogs (Canis Familiaris, Linnaeus, 1758)”. Brazilian Journal of Veterinary Research and Animal Science, vol. 41, no. 1, Feb. 2004, pp. 20-24, https://doi.org/10.1590/S1413-95962004000100004.