Language and languages - Origin.

The talking ape : how language evolved by: Burling, Robbins (Language materials, printed)

Routes to child language : evolutionary and developmental precursors by: Blake, Joanna (Language materials, printed)

The seeds of speech language origin and evolution by: Aitchison, Jean (Language materials, printed)

The evolutionary emergence of language : social function and the origins of linguistic form by: Studdert-Kennedy, Michael; Knight, Chris; Hurford, James R. (Language materials, printed)