Alam, Waqas, Mobasher Ahmad Saeed, and Khan Muhammad Yaqub. “Intrathecal Tramadol May Cause Respiratory Depression”. Anaesthesia, Pain & Intensive Care (January 20, 2019): 87-89. Accessed June 30, 2024. https://apicareonline.com/index.php/APIC/article/view/143.