title: [Diurnal periodical cycle of cardiac activity in children in the ontogenesis according to ECG data].
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn
vernacular_title: O sutochnoĭ periodike serdechnoĭ deiatel'nosti u deteĭ v ontogeneze po dannym elektrokardiograficheskikh issledovaniĭ.