Khaomuangnoi, J., T. Pamornsinlapathum, A. Phadungwitthayakorn, and A. Pamarapa. “Results and Predictive Factors for Survival of Periampullary Cancer Patients at Uttaradit Hospital”. The Thai Journal of Surgery, vol. 37, no. 4, Oct. 2016, pp. 133-41, https://he02.tci-thaijo.org/index.php/ThaiJSurg/article/view/224660.