E. de Mattos Junior, G. J. von G. dos Santos, C. Russo, J. P. E. Saut, and S. A. Headley, “Evaluation of cortisol and glycemia levels of dogs anesthetized with sevoflurane and premedicated with either butorphanol or phetidine”, Sem. Ci. Agr., vol. 30, no. 2, pp. 425–434, Jul. 2009.