De Marco, Viviani, and Carlos Eduardo Larsson. “Hypothyroidism in Dogs: Study of Cervical Ultrasonography As Diagnosis Methodology”. Brazilian Journal of Veterinary Research and Animal Science, vol. 43, no. 6, Dec. 2006, pp. 747-53, https://doi.org/10.11606/issn.1678-4456.bjvras.2006.26552.