Pratama, Nata, et al. “Prevalence of Crohnƒs Disease in Endoscopic Unit Cipto Mangunkusumo Hospital”. The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy, vol. 12, no. 2, Jan. 2011, pp. 85-88, doi:10.24871/122201185-88.