References for "Overcoming insomnia"
Becker PM. "Insomnia: Prevalence, Impact, Pathogenesis, Differential Diagnosis, and Evaluation," Psychiatric Clinics of North America (Dec. 2006): Vol. 29, No. 4, pp. 855–70. www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17118272
Epstein L. Improving Sleep: A Guide to a Good Night's Rest (Harvard Health Publishing, 2010).