JIN MUN, Hyung; HEE HAN, Kun. Tetris security keypads design with higher security using alignment and padding. International Journal of Engineering and Technology, [S. l.], v. 7, n. 2.33, p. 11–14, 2018. DOI: 10.14419/ijet.v7i2.33.13838. Disponível em: https://mail.sciencepubco.com/index.php/IJET/article/view/13838.. Acesso em: 17 aug. 2025.