A longitudinal study of preschoolers' language-based bedtime routines, sleep duration, and well-being.
Hale L, Berger LM, LeBourgeois MK, Brooks-Gunn J. A longitudinal study of preschoolers' language-based bedtime routines, sleep duration, and well-being. J Fam Psychol. 2011 Jun; 25(3):423-33.