1. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, College of Medicine, Soonchunhyang University, Bucheon, Republic of Korea
2. Medical Library, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
3. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
4. Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Republic of Korea
5. Yonsei Liver Cancer, Severance Hospital, Seoul, Republic of Korea
6. Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea