Cheney, D. L. and Seyfarth, R. M. (2005) Constraints and preadaptations in the earliest stages of language evolution. The Linguistic Review , 22(2-4):135--159.

Cheney, D. L. and Seyfarth, R. M. (2005) Constraints and preadaptations in the earliest stages of language evolution. The Linguistic Review, 22(2-4):135--159.

2007	-	The Role of Anticipation in the Emergence of Language - Swarup,Gasser	::
2008	-	Cost and complexity: Selection for speech and language - Locke	::