?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aufirst=Mariana&rft.au=22084475%2C+Mariana&rft.aulast=22084475&rft.date=February+2013&rft.tpages=41&rft.title=MEMBANGUN+SISTEM+CAPTCHA+BERBASIS+GAMBAR+DAN+SUARA+DENGAN+PENDEKATAN+ACCESSIBILITY+DAN+USABILITY&rft.degree=Bachelor&rft.inst=Universitas+Kristen+Duta+Wacana