AcharyaM., PanagiotopoulosN., CohenP., AhmadR. and JiaoL. (2013) “Poorly-Differentiated Signet-Ring Cell Carcinoma of the Ampulla of Vater: Report of a Rare Malignancy”, JOP. Journal of the Pancreas, 14(2), pp. 190-194. doi: 10.6092/1590-8577/1267.