Bonnet MH, and Arand DL. Clinical effects of sleep fragmentation versus sleep deprivation. Sleep Med Rev 7: 297-310, 2003.
Borbely AA. A two process model of sleep regulation. Hum Neurobiol 1: 195-204, 1982.
Foley D, Ancoli-Israel S, Britz P, and Walsh J. Sleep disturbances and chronic disease in older adults: results of the 2003 National Sleep Foundation Sleep in America Survey. J Psychosom Res 56: 497-502, 2004.