Ravi S, Pradeep YM, Shankarlal J, and Rajanna B. “Study of Risk Factors Predicting Increased Morbidity and Mortality in Perforated Peptic Ulcer-Our Institutional Perspective”. International Journal of Health and Clinical Research, vol. 4, no. 14, Aug. 2021, pp. 355-60, https://ijhcr.com/index.php/ijhcr/article/view/2362.