@article{lopes2011symbiotic,
  title={Symbiotic filtering for spam email detection},
  author={Lopes, C. and Cortez, P. and Sousa, P. and Rocha, M. and Rio, M.},
  journal={Expert Systems with Applications},
  volume={38},
  number={8},
  pages={9365-9372},
  year={2011},
  publisher={Elsevier}
}