Name Info Provider Link
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S0277-9536(18)30620-8
Choosing a Doctor or Health Care Service free resource MedlinePlus Health Information https://medlineplus.gov/choosingadoctororhealthcareservice.html
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/30391641/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/30391641