M. K. Regar, G. S. Choudhary, C. Nogia, D. K. Pipal, A. Agrawal, and H. Srivastava, “Comparison of Alvarado and RIPASA scoring systems in diagnosis of acute appendicitis and correlation with intraoperative and histopathological findings”, Int Surg J, vol. 4, no. 5, pp. 1755–1761, Apr. 2017.