N. Syabila Zabidi, N. Mohd Norowi, and R. Wirza O.K. Rahmat, “A Usability Evaluation of Image and Emojis in Graphical Password”, IJET, vol. 7, no. 4.31, pp. 400–407, Dec. 2018, doi: 10.14419/ijet.v7i4.31.23719.