Singh , V, VK Kurrey, O Khandwal, and S Phuljhele. 2014. “Evaluation of Lung Function by Spirometry in 12-14 Yrs Adolescents in Schools of Raipur City Chhattisgarh”. International Journal of Medical Science Research and Practice 1 (1):9-15. https://ijmsrp.isroset.org/index.php/j/article/view/3.