Dr. P.D. Khandait , Rahul Khandait, Dr. S. P. Khandait. “A Case Study of Comparative Analysis of Pollution Indicators across Regions of Delhi and Mumbai During Covid-19”. International Journal of Advanced Science and Technology, Vol. 29, no. 8s, June 2020, pp. 4097-06, http://sersc.org/journals/index.php/IJAST/article/view/25423.