Name Info Provider Link
subscription/membership/fee required Atypon https://journals.sagepub.com/doi/10.1177/155005940803900412?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
Mercury free resource MedlinePlus Health Information https://medlineplus.gov/mercury.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=19044221.ui