Sleep problems in children and their relationship with early disturbances of the waking-sleeping rhythms.
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D006306:Health Surveys; D006801:Humans; D012189:Retrospective Studies; D012890:Sleep; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000503:physiopathology*