1. Alegria, J., & Noirot, E. (1978). Neonate orientation behavior towards human voice.International Journal of Behavioral Development, 1, 291–312.
2. American Psychiatric Association. (1980).Diagnostic and statistical manual of mental disorders (3rd ed.). Washington, DC: Author.
3. Bates, E., Benigni, L., Camaioni, L., Bretherton, I., & Volterra, V. (1979).The emergence of symbols: Cognition and communication in infancy. New York: Academic Press.
4. Bronfenbrenner, U. (1979).The ecology of human development: Experiments by nature and design. Cambridge, MA: Harvard University Press.
5. Butterfield, E. C., & Cairns, G. F. (1976). The infant's auditory environment. In T. D. Tjossem (Ed.),Intervention strategies for high risk infants and young children. Baltimore: University Press.