[PHASES OF SLEEP AND SPONTANEOUS SMILES].
D005149:Facial Expression; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D010827:Physiology; D012890:Sleep
FACIAL EXPRESSION; INFANT; INFANT, NEWBORN; PHYSIOLOGY; SLEEP
PHASES DE SOMMEIL ET SOURIRES SPONTAN'ES.