R. Mariappan, and M. Murugalingam. “On $m$-$\delta$-$I$-Open Sets and $m$-$\delta$-$I$-Continuity”. International Journal of Mathematics And Its Applications, vol. 6, no. 2 - A, May 2018, pp. 313-7, https://ijmaa.in/index.php/ijmaa/article/view/677.