Macrea M, Oczkowski S, Rochwerg B, Branson RD, Celli B, Coleman JM, Hess DR, Knight SL, Ohar JA, Orr JE, Piper AJ, Punjabi NM, Rahangdale S, Wijkstra PJ, Yim-Yeh S, Drummond MB, Owens RL. Long-Term Noninvasive Ventilation in Chronic Stable Hypercapnic Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2020 08 15; 202(4):e74-e87.