Sikarwar, Ankit, and Ritu Rani. “Assessing the Immediate Effect of Covid-19 Lockdown on Air Quality: A Case Study of Delhi, India”. Journal of Environmental Geography 13, no. 3-4 (December 31, 2020): 27–33. Accessed April 29, 2024. https://ojs.bibl.u-szeged.hu/index.php/jengeo/article/view/43732.