Bahri ABAYLI, et al. “Serum Profile of T Helper 1 and T Helper 2 Cytokines in Patients With Chronic Hepatitis C Virus Infection”. Turkish Journal of Gastroenterology, vol. 14, no. 1, July 2019, pp. 7-11, https://tjg.avesjournals.com/index.php/tjg/article/view/1821.