Mandal, M., Bandyopadhyay, A., Datta, A., & Chowdhury, S. G. (2015). Comparison of lower limit of normal values with a fixed ratio assessed by spirometry in obstructive and restrictive lung diseases in Indian population. International Journal of Clinical and Experimental Physiology, 2(1), 66-72. Retrieved from https://ijcep.org/index.php/ijcep/article/view/49