Shringi, Sameeksha, Mahesh Kumar Mishra, and Aviral Kumar Singh. “ Its Correlation With Spirometry Grading”. Pakistan Journal of Chest Medicine 26, no. 4 (January 10, 2021): 187–193. Accessed August 25, 2026. https://pjcm.net/index.php/pjcm/article/view/670.