Monteiro, Eduardo Raposo, et al. “Sedative and Cardiorespiratory Effects of Methadone, Alone or in Combination With Acepromazine or Xylazine, in Cats”. Brazilian Journal of Veterinary Research and Animal Science, vol. 45, no. 4, Aug. 2008, pp. 289-97, https://doi.org/10.11606/issn.1678-4456.bjvras.2008.26688.