Petitto&Marenette1991
(Ohjattu sivulta Lähde:Petitto & Marenette 1991)
Pettitto, Laura A. & Marentette, Pauline (1991) Babbling in the Manual Mode: Evidence for the Ontogeny of Language. Science 25: 1493– 96.
Pettitto, Laura A. & Marentette, Pauline (1991) Babbling in the Manual Mode: Evidence for the Ontogeny of Language. Science 25: 1493– 96.