Susilawati, Tri Nugraha, and Atik Susianto. “A Systematic Review of the Frequency of Regulatory T Cells in Hepatitis B and Hepatitis C”. The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy, vol. 20, no. 3, July 2020, pp. 161-8, doi:10.24871/2032019161-168.