Parzefall, Jurgen, et al. “Whipple Procedure in a Patient With Duplicated Portal Vein and Other Major Abnormalities in Vascular Anatomy of the Upper Abdomen – A Case Report of a Rare Finding”. Archives of Case Reports, vol. 9, no. 11, Nov. 2025, pp. 366-9, doi:10.29328/journal.acr.1001174.