Name	Info	Provider	Link
COPD	free resource	MedlinePlus Health Information	https://medlineplus.gov/copd.html
	free resource	Primary Care Respiratory Society UK	https://doi.org/10.4104/pcrj.2011.00066
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21785813/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/21785813
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:21785813