Coskun, S., T. Baha Demirbas, K. Tevfik Uprak, A. Emre Atici, and C. Sevket Yegen. “Effects of Preoperative Drainage on Postoperative Complications in Patients With Periampullary Tumors”. Annals of Medical Research, vol. 26, no. 7, May 2021, pp. 1301-8, http://www.annalsmedres.org/index.php/aomr/article/view/1277.