Raza, A., Malik, M. I., & Jamal, Y. (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://www.pafmj.org/PAFMJ/article/view/528