Chaudhary, Waqas Ashraf, Jennifer Kennett RN, Ishrat Bano, and Daniel J. William. 2019. “Ketamine As an Adjuvant to Opioids for Cancer Pain Management”. Anaesthesia, Pain & Intensive Care, February, 174-78. https://apicareonline.com/index.php/APIC/article/view/500.