1. Characteristics of insomnia in the United States: results of the 1991 National Sleep Foundation Survey;I. Sleep,1999
2. Prevalence, associated risks, and treatment patterns of insomnia;J Clin Psychiatry,2005
3. Insomnia and its treatment: prevalence and correlates;Arch Gen Psychiatry,1985
4. Sleep complaints among elderly persons: an epidemiologic study of three communities;Sleep,1995
5. Sleep Incidence and remission of insomnia among elderly adults: an epidemiologic study of 6,800 persons over three years;Sleep,1999