Sumiti Narayan Tewari , Anita Shukla. “E-Learning: An Effective Virtual Way to Understand the Physical World”. International Journal of Emerging Trends in Science and Technology, Vol. 4, no. 08, Aug. 2017, pp. 5665-8, http://igmpublication.org/ijetst.in/index.php/ijetst/article/view/1319.