Raza, Ahmad, Mahmood Iqbal Malik, and Yousaf Jamal. 2014. “COMPARISON OF NIPPV WITH STANDARD TREATMENT IN PATIENTS WITH ACUTE EXACERBATIONS OF COPD IN TERMS OF IMPROVEMENT IN ABGS AND HOSPITAL STAY: COPD and Hospital Stay”. Pakistan Armed Forces Medical Journal 64 (1): 46-50. https://pafmj.org/PAFMJ/article/view/528.