@article{codevilla_castilhos_bergold_2013,  title={A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations},  volume={49},  ISSN={1984-8250},  url={https://doi.org/10.1590/S1984-82502013000100002},  DOI={10.1590/S1984-82502013000100002},  number={1},  journal={Brazilian Journal of Pharmaceutical Sciences},  publisher={Universidade de São Paulo, Faculdade de Ciências Farmacêuticas},  author={Codevilla, Cristiane Franco and Castilhos, Tamara dos Santos and Bergold, Ana Maria},  year={2013},  month={Jan},  pages={1–11} }