“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 ”, Ann Med Res , vol. 26, no. 3, pp. 0495–0498, May 2021, Accessed: Apr. 12, 2025. [Online]. Available: http://annalsmedres.org/index.php/aomr/article/view/1318