Khan, Amanat, and Tariq Mufti. 2004. “A Comparison of Analgesic Efficacy of Ketorolac and Piroxicam for Postoperative Pain Relief After Cholecystectomy”. Anaesthesia, Pain & Intensive Care 8 (2). https://mail.apicareonline.com/index.php/APIC/article/view/882.