Buettner S, Wilson A, Margonis GA, Gani F, Ethun CG, Poultsides GA, Tran T, Idrees K, Isom CA, Fields RC, Krasnick B, Weber SM, Salem A, Martin RC, Scoggins CR, Shen P, Mogal HD, Schmidt C, Beal E, Hatzaras I, Shenoy R, Maithel SK, Pawlik TM. Assessing Trends in Palliative Surgery for Extrahepatic Biliary Malignancies: A 15-Year Multicenter Study. J Gastrointest Surg. 2016 08; 20(8):1444-52.