Dynamics of sleep-wake transitions during sleep C.-C. Lo, L. A. Nunes Amaral, S. Havlin, P. Ch. Ivanov, T. Penzel, J.-H. Peter and H. E. Stanley Europhys. Lett., 57 5 (2002) 625-631 Published online: 01 September 2002 DOI: 10.1209/epl/i2002-00508-7