Ozdemir, Gorkem, and Alper Sözütek. “Comparison of Preoperative and Postoperative Frailty in Elderly Following Gastrointestinal Cancer Surgery”. The European Research Journal 11, no. 4 (July 3, 2025): 753–761. Accessed April 5, 2026. https://eurj.org.tr/article/view/1070.