COMPARISON OF THE EFFECTS OF INTRATHECAL TRAMADOL AS AN ADJUVANT WITH BUPIVACAINE IN PATIENTS UNDERGOING INFRA-UMBILICAL SURGERIES AT TERTIARY CARE HOSPITAL, KARACHI. RMSR. 2025;3(7):110-116. Accessed July 17, 2025. http://www.thermsr.com/index.php/Journal/article/view/1442