Venkata Srinivasu Veesam, and Bandaru Satish Babu. “Evaluation of Captcha Technologies towards Graphical Password Scheme”. International Journal of Computer Engineering in Research Trends 2, no. 2 (February 28, 2015): 98–106. Accessed July 1, 2026. https://www.ijcert.org/index.php/ijcert/article/view/134.