Kumar, Ankur, Bilal Ahmad, and Vineet Tyagi. “A Comparative Study of Haemodynamic Responses of Butorphanol and Fentanyl While Surgeries”. International journal of health sciences 6, no. S1 (May 9, 2022): 9381–9390. Accessed August 18, 2024. https://sciencescholar.us/journal/index.php/ijhs/article/view/7136.