@inproceedings{shirali2008children,
  author    = {S. Shirali-Shahreza and M. Shirali-Shahreza},
  title     = {CAPTCHA for Children},
  booktitle = {Proceedings of Third International Conference on System of Systems Engineering (SoSE 2008)},
  address   = {Monterey, California, USA},
  month     = jun,
  year      = {2008},
  doi       = {10.1109/SYSOSE.2008.4724188},
  url       = {https://doi.org/10.1109/SYSOSE.2008.4724188}
}