1. Sleep and Wakefulness;Kleitman,1972
2. The Sleeping Brain,1972
3. Awakening from sleep;Åkerstedt;Sleep Med Rev,2002
4. Insomnia in the geriatric patient;Avidan;Clin Cornerstone,2003
5. Insomnia: epidemiology, characteristics, and consequences;Roth;Clin Cornerstone,2003