@article{paula_villar_gaspar_2003,  title={Comparison of four extraction methods to detect hepatitis A virus RNA in serum and stool samples},  volume={7},  ISSN={1413-8670},  url={https://doi.org/10.1590/S1413-86702003000200007},  DOI={10.1590/S1413-86702003000200007},  number={2},  journal={Brazilian Journal of Infectious Diseases},  publisher={Brazilian Society of Infectious Diseases},  author={Paula, Vanessa Salete de and Villar, Livia Melo and Gaspar, Ana Maria Coimbra},  year={2003},  month={Apr},  pages={135–141} }