Name Info Provider Link
Insomnia free resource MedlinePlus Health Information https://medlineplus.gov/insomnia.html
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=19584739.ui
subscription/membership/fee required Wolters Kluwer https://doi.org/10.1097/YIC.0b013e32832e9b08