(Inggris)"Abnormal Prothrombin (DES-γ-Carboxy Prothrombin) in Hepatocellular Carcinoma". Departments of Surgery and Pathology, University of Pittsburgh School of Medicine and the Veterans Administration Medical Center; A. Nakao, A. Virji, Y. Iwaki, B. Carr, S. Iwatsuki, dan E. Starzl. Diakses tanggal 2010-12-10.