MACHARLA BHANU KUMAR, and K.KRANTHI KUMAR. “Enhancing CAPTCHA Based Image Authentication for E-Mail ID and Password”. International Journal of Computer Engineering in Research Trends 2, no. 12 (December 31, 2015): 1251–1256. Accessed August 15, 2026. https://www.ijcert.org/index.php/ijcert/article/view/408.