Nishikawa, H., Y. Osaki, E. Iguchi, H. Takeda, Y. Ohara, A. Sakamoto, K. Hatamaru, S. Henmi, S. Saito, A. Nasu, R. Kita, and T. Kimura. “Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma: Clinical Outcome and Safety in Elderly Patients”. Journal of Gastrointestinal and Liver Diseases, Vol. 21, no. 4, Dec. 2012, pp. 397-05,