@article{esteves_spaine_cedenho_2007,  title={Effects of pentoxifylline treatment before freezing on motility, viability and acrosome status of poor quality human spermatozoa cryopreserved by the liquid nitrogen vapor method},  volume={40},  ISSN={0100-879X},  url={https://doi.org/10.1590/S0100-879X2006005000118},  DOI={10.1590/S0100-879X2006005000118},  number={7},  journal={Brazilian Journal of Medical and Biological Research},  publisher={Associação Brasileira de Divulgação Científica},  author={Esteves, S.C. and Spaine, D.M. and Cedenho, A.P.},  year={2007},  month={Jul},  pages={985–992} }