R. E. Beggs, M. E. Kelly, O. Eltayeb, P. Crotty, R. McDermott, and P. F. Ridgway, “Large Cell Neuroendocrine Carcinoma of the Ampulla of Vater”, JOP. J Pancreas (Online), vol. 13, no. 5, pp. 470–475, Sep. 2012.