@inproceedings{oai:shizuoka.repo.nii.ac.jp:00014024,
 author = {Kani, Junya and Nishigaki, Masakatsu},
 book = {Human Aspects of Information Security, Privacy, and Trust},
 month = {Jul},
 note = {application/pdf},
 pages = {39--48},
 publisher = {Springer, Berlin, Heidelberg},
 title = {Gamified CAPTCHA},
 volume = {8030},
 year = {2013}
}