M. K., Y., P., S., D. M., V., & U. K., A. R. (2017). A comparative study of epidural tramadol with epidural pentazocine for postoperativeanalgesia in patients undergoing lower abdominal surgeries. International Journal of Basic & Clinical Pharmacology, 6(10), 2441–2445. https://doi.org/10.18203/2319-2003.ijbcp20174373