@article{sobreiro_lucon_pasqualotto_hallak_athayde_arap_2005,  title={Semen analysis in fertile patients undergoing vasectomy: reference values and variations according to age, length of sexual abstinence, seasonality, smoking habits and caffeine intake},  volume={123},  ISSN={1516-3180},  url={https://doi.org/10.1590/S1516-31802005000400002},  DOI={10.1590/S1516-31802005000400002},  number={4},  journal={Sao Paulo Medical Journal},  publisher={Associação Paulista de Medicina - APM},  author={Sobreiro, Bernardo Passos and Lucon, Antonio Marmo and Pasqualotto, Fábio Firmbach and Hallak, Jorge and Athayde, Kelly Silveira and Arap, Sami},  year={2005},  pages={161–166} }