Saleh , Amin J., Liangbin Zhang, Sally M. Hadi, and Wen Ouyang. 2014. “A Priming Dose of Intravenous Ketamine-Dexmedetomidine Suppresses Fentanyl-Induced Coughing: A Double-Blind, Randomized, Controlled Study”. Upsala Journal of Medical Sciences 119 (4):333–337. https://doi.org/10.3109/03009734.2014.968270.