Sanli, M., and M. Ucar. “Comparison of the Effects of Adding Fentanyl or Remifentanil to Propofol in Colonoscopy Sedoanalgesia on Visual Analog Scale and Recovery: A Prospective Double-Blind Study”. Annals of Medical Research, vol. 26, no. 3, May 2021, pp. 0495-8, http://www.annalsmedres.org/index.php/aomr/article/view/1318.