Brain Basics: Understanding Sleep. Office of Communications and Public Liaison, National Institute of Neurological Disorders and Stroke, US National Institutes of Health, Bethesda, MD. 2017 [2013-12-10]. (原始内容存档于2007-10-11).
Brain Basics: Understanding Sleep. Office of Communications and Public Liaison, National Institute of Neurological Disorders and Stroke, US National Institutes of Health, Bethesda, MD. 2017 [2013-12-10]. (原始内容存档于2007-10-11).