title: Respiratory frequency according to sleep states and age in normal premature infants: a comparison with full term infants.
mesh_terms: D000367:Age Factors; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D012119:Respiration; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors; D014939:Work of Breathing