Bright light resets the human circadian pacemaker independent of the timing of the sleep-wake cycle. - Czeisler,C.A.; Allan,J.S.; Strogatz,S.H.; Ronda,J.M.; Sanchez,R.; Rios,C.D.; Freitag,W.O.; Richardson,G.S.; Kronauer,R.E. (Science, 1986)