Sharma, A. ., S. . kumar, J. . G, and S. P. . Singh. “COMPARISON OF OXYGEN SATURATION PULMONARY FUNCTION AND QUALITY OF LIFE BETWEEN HILL AND PLAIN AMONG COPD PATIENTS”. International Journal of Physiotherapy, vol. 3, no. 3, June 2016, pp. 346-50, doi:10.15621/ijphy/2016/v3i3/100842.