1. Reddy V (1999) Prelinguistic communication. In: Barrett MD (ed) The development of language. Psychology Press, East Sussex, UK, pp 25–50
2. McCathren RB, Warren SF, Yoder PJ (1996) Prelinguistic predictors of later language development. In: Cole KN, Dale PS, Thal DJ (eds) Assessment of communication and language. Brookes, Baltimore, MD, pp 57–75
3. Wetherby A, Prizant B (1993) Communication and symbolic behavior scales- Normed Edition. Chicago, IL, Applied Symbolix
4. Stern D (1985) The interpersonal world of the infant. Basic Books, New York
5. Wetherby AM, Prizant BM (2002) Communication and symbolic behavior scales: developmental profile (1st normed ed.). Baltimore, MD, Brookes