Alyaa A. Hafedh, et al. “The Frequency of Anti-Hepatitis B Core Antibody in Negative Hepatitis B Surface Antigen Blood Donors in Thi-Qar Province”. University of Thi-Qar Journal, vol. 10, no. 3, Apr. 2019, pp. 1-5, doi:10.32792/utj.v10i3.29.