I.N. Sodhar, A.H. Jalbani, A.H. Buller, and A.N. Sodhar. “Tools Used In Online Teaching and Learning through Lock-Down”. International Journal of Computer Engineering in Research Trends, vol. 7, no. 8, Aug. 2020, pp. 36-40, https://www.ijcert.org/index.php/ijcert/article/view/608.