@article{oliveira_romanha_alves_viana_zani_2004,  title={An improved HPLC method for the quantitation of 6-mercaptopurine and its metabolites in red blood cells},  volume={37},  ISSN={0100-879X},  url={https://doi.org/10.1590/S0100-879X2004000500004},  DOI={10.1590/S0100-879X2004000500004},  number={5},  journal={Brazilian Journal of Medical and Biological Research},  publisher={Associação Brasileira de Divulgação Científica},  author={Oliveira, B.M. and Romanha, A.J. and Alves, T.M.A. and Viana, M.B. and Zani, C.L.},  year={2004},  month={May},  pages={649–658} }