Leite, Ceci Ribeiro, et al. “Cardiorespiratory and Hemogasometric Effects of Epidural Ketamine and Its Associations With Morphine and Xylazine in Sheep”. Semina: Ciências Agrárias, vol. 42, no. 1, Jan. 2021, pp. 241-54, doi:10.5433/1679-0359.2021v42n1p241.