Stevenson, Ryan, Steven Libutti, and Muhammad Saif. “Prognostic and Predictive Biomarkers in Gastroenteropancreatic Neuroendocrine Tumors”. JOP. Journal of the Pancreas 14, no. 2 (March 10, 2013): 155-157. Accessed June 30, 2022. http://www.serena.unina.it/index.php/jop/article/view/1472.