Jena, M., S. M. Mishra, S. Pradhan, S. Jena, and S. S. Mishra. “Chronic Pain, Its Management and Psychological Issues: A Review”. Asian Journal of Pharmaceutical and Clinical Research, vol. 8, no. 5, Sept. 2015, pp. 42-47, https://journals.innovareacademics.in/index.php/ajpcr/article/view/7403.