Abdullah, Murdani, Fumiaki Kitahara, Tadashi Sato, Yuichiro Kojima, Abdul Aziz Rani, and Masayuki A. Fujino. 2003. “Life Style Factors Influencing Serum Pepsinogen Levels in Healthy Japanese: A Prospective Study”. The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy 4 (1):6-10. https://doi.org/10.24871/4120036-10.