Boomsma, Martijn, Ilse van Dop, Marleen Willems, and Abdulbaqi Al-Toma. 2009. “An Unusual Cause of Upper Gastrointestinal Obstruction in an Adult: Annnular Pancreas”. Journal of Gastrointestinal and Liver Diseases 18 (1):117-24. https://www.jgld.ro/jgld/index.php/jgld/article/view/2009.1.194.