Vadhanan, P., and K. Balakrishnan. “Comparison of Postoperative Analgesia With 0.8 Mg and 1.6 Mg Intrathecal Nalbuphine; A Randomized Controlled Trial”. Anaesthesia, Pain & Intensive Care, Jan. 2019, pp. 37-43, https://mail.apicareonline.com/index.php/APIC/article/view/156.