@article{afyon_2016,  title={What are the causes and outcomes of the coexistence of HBsAg and anti-HBs?},  volume={20},  ISSN={1413-8670},  url={https://doi.org/10.1016/j.bjid.2016.01.009},  DOI={10.1016/j.bjid.2016.01.009},  number={3},  journal={Brazilian Journal of Infectious Diseases},  publisher={Brazilian Society of Infectious Diseases},  author={Afyon, Murat},  year={2016},  month={May},  pages={318–319} }