1. Regularly occurring periods of eye motility and concomitant phenomena during sleep;Aserinsky;Science,1953
2. Wake up America, national commission on sleep disorders,1993
3. Sleep in America 1995 gallup poll: updated CA,1999
4. Commercial and public transportation impact;Stoohs,2005
5. Social jetlag: misalignment of biological and social time;Wittmann;Chronobiol Int,2006