@InProceedings{Bursztein10,
    author    =  {Elie Bursztein and Steven Bethard and John C. Mitchell and Dan Jurafsky and Celine Fabry},
    title     = {{How good are humans at solving CAPTCHAs? A large scale evaluation}},
    booktitle = {IEEE Symposium on Security and Privacy},
    year      = {2010},
}