Name Info Provider Link
COPD free resource MedlinePlus Health Information https://medlineplus.gov/copd.html
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22848155/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/22848155
free resource Dove Medical Press https://dx.doi.org/10.2147/COPD.S31378