A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2019; you can also visit the original URL.
The file type is
Epidemiology Older studies that used cell culture and serology to determine the etiology of COPD exacerbations detected viruses in only 10-20% of cases  . More recent studiesdoi:10.1097/mcp.0b013e3282f4a99f pmid:18303415 fatcat:a2itbifip5h25mym4edormcqpm