Name Info Provider Link
subscription/membership/fee required Atypon https://www.nejm.org/doi/10.1056/NEJMp2020962?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
Choosing a Doctor or Health Care Service free resource MedlinePlus Health Information https://medlineplus.gov/choosingadoctororhealthcareservice.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=32937061.ui