Name	Info	Provider	Link
Flu	free resource	MedlinePlus Health Information	https://medlineplus.gov/flu.html
	free resource	Public Library of Science	https://dx.plos.org/10.1371/journal.pone.0210353
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/30633778/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/30633778
Full text from	free resource	Diposit Digital de la Universitat de Barcelona	http://hdl.handle.net/2445/102375