↑Hirshkowitz, Max (2004). "10, Neuropsychiatric Aspects of Sleep and Sleep Disorders (pp. 315–340)". ใน Stuart C. Yudofsky and Robert E. Hales (บ.ก.). Essentials of neuropsychiatry and clinical neurosciences (4 ed.). Arlington, Virginia, USA: American Psychiatric Publishing. ISBN978-1-58562-005-0. สืบค้นเมื่อ 2009-12-06. ...insomnia is a symptom. It is neither a disease nor a specific condition. (p. 322)
↑American College of Physicians (2008).Annals of Internal Medicine, 148, 1, p. ITC1-1
↑Zahn, Dorothy, "Insomnia: CPJRPC", The Canadian Pharmaceutical Journal, Oct 2003
↑"Dyssomnias"(PDF). WHO. pp. 7–11. สืบค้นเมื่อ 2009-01-25.
↑Erman, Milton K. (2007). "Insomnia: Comorbidities and Consequences". Primary Psychiatry. 14 (6): 31–35. Two general categories of insomnia exist, primary insomnia and comorbid insomnia.
↑World Health Organization (2007). "Quantifying burden of disease from environmental noise"(PDF). p. 20. คลังข้อมูลเก่าเก็บจากแหล่งเดิม(PDF)เมื่อ 2010-11-23. สืบค้นเมื่อ 2010-09-22. In his e-mail dated 10.8.2005, Colin Mathers gives the following statement referring to this question: ‘Primary insomnia is sleeplessness that is not attributable to a medical, psychiatric or environmental cause. …’
↑Riemann, Dieter (2002). "Consequences of Chronic (Primary) Insomnia: Effects on Performance, Psychiatric and Medical Morbidity - An Overview". Somnologie - Schlafforschung und Schlafmedizin. 6 (3): 101–108. doi:10.1046/j.1439-054X.2002.02184.x. {{cite journal}}: ไม่รู้จักพารามิเตอร์ |coauthors= ถูกละเว้น แนะนำ (|author=) (help)