Name	Info	Provider	Link
	free resource	BioMed Central	https://hqlo.biomedcentral.com/articles/10.1186/1477-7525-9-119
Insomnia	free resource	MedlinePlus Health Information	https://medlineplus.gov/insomnia.html
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22208861/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22208861
Full text from	free resource	White Rose Research Online	https://eprints.whiterose.ac.uk/115431/