Afsana Afzal, «UC Berkeley Study Shows Dream Sleep Relieves Emotional Stress,» The Daily Californian, November 29, 2011, .
377
Rachel Leproult, Georges Copinschi, Orfeu Buxton, and Eve Van Cauter, «Sleep Loss Results in an Elevation of Cortisol Levels the Next Evening,» Sleep: Journal of Sleep Research & Sleep Medicine 20 (1997): 865–70.
