Arya, V., A. Gupta, and A. Malhotra. “Correlation of Neutrophil Lymphocyte Ratio With the Severity of Chronic Obstructive Pulmonary Disease: A Cross Sectional Study”. International Journal of Health and Clinical Research, vol. 3, no. 12, Dec. 2020, pp. 90-95, https://ijhcr.com/index.php/ijhcr/article/view/463.