@article{andersen_bignotto_tufik_2007,  title={Effect of sildenafil (Viagra®) on the genital reflexes of paradoxical sleep-deprived male rats},  volume={40},  ISSN={0100-879X},  url={https://doi.org/10.1590/S0100-879X2006005000180},  DOI={10.1590/S0100-879X2006005000180},  number={11},  journal={Brazilian Journal of Medical and Biological Research},  publisher={Associação Brasileira de Divulgação Científica},  author={Andersen, M.L. and Bignotto, M. and Tufik, S.},  year={2007},  month={Nov},  pages={1473–1480} }