Name Info Provider Link
subscription/membership/fee required Atypon https://journals.sagepub.com/doi/10.1177/21650799221113057?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
COPD free resource MedlinePlus Health Information https://medlineplus.gov/copd.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=35997067.ui