1. Regularly occurring periods of eye motility, and concomitant phenomena, during sleep;Aserinsky;Science,1953
2. The Paradox of Sleep, the story of dreaming.;Jouvet,1999
3. The influence of gravity on REM sleep;Gonfalone;Open Access Anim Physiol,2015
4. The enchanted world of sleep;Lavie,1996
5. http://www.dreams.co.uk/.