Buettner S, van Vugt JL, Gani F, Groot Koerkamp B, Margonis GA, Ethun CG, Poultsides G, Tran T, Idrees K, Isom CA, Fields RC, Krasnick B, Weber SM, Salem A, Martin RC, Scoggins C, Shen P, Mogal HD, Schmidt C, Beal E, Hatzaras I, Shenoy R, Maithel SK, Guglielmi A, IJzermans JN, Pawlik TM. A Comparison of Prognostic Schemes for Perihilar Cholangiocarcinoma. J Gastrointest Surg. 2016 10; 20(10):1716-24.