Kiran thorat, Nishant Mehare, Amarnath Sutar, Vaishnavi Lavhale, and Prof. Gaurav Gupta. “SHOULDER SURFING ATTACK RESISTENT GRAPHICAL AUTHENTICATION SYSTEM”. International Journal of Advance Research in Engineering, Science & Technology, vol. 5, no. 5, May 2018, pp. 216-21, https://ijarest.org/index.php/ijarest/article/view/1725.