Name Info Provider Link
subscription/membership/fee required HighWire http://perspectivesinmedicine.cshlp.org/cgi/pmidlookup?view=long&pmid=31871239
Flu free resource MedlinePlus Health Information https://medlineplus.gov/flu.html
free resource PubMed Central https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/31871239/
free resource Europe PubMed Central https://europepmc.org/abstract/MED/31871239