S. Pious Missier, C. Reena, and G. Mahadevan. “Contra Semi*$\delta$-Continuous Functions in Topological Spaces”. International Journal of Mathematics And Its Applications, vol. 5, no. 4 - A, Oct. 2017, pp. 19-30, http://ijmaa.in/index.php/ijmaa/article/view/1234.