Name	Info	Provider	Link
Tears	free resource	MedlinePlus Health Information	https://medlineplus.gov/tears.html
	subscription/membership/fee required	Nature Publishing Group	https://doi.org/10.1038/eye.2011.105
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21701529/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/21701529
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:21701529