Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) W. Xu and J. P. Collet and S. Shapiro and Y. Lin and T. Yang and C. Wang and J. Bourbeau,Negative impacts of unreported COPD exacerbations on health-related quality of life at 1 year,European Respiratory Journal,0903-1936,European Respiratory Society (ERS),2009-11-06,35,5,1022-1030,https://cir.nii.ac.jp/crid/1360292618762452224,https://doi.org/10.1183/09031936.00079409