Hauser & Fitch 2003 Hauser, Marc D.; Fitch, W. Tecumseh (2003). „What are the uniquely human components of the language faculty?”. Ур.: M.H. Christiansen and S. Kirby. Language Evolution: The States of the Art(PDF). Oxford University Press. Архивирано из оригинала(PDF) 8. 8. 2014. г.
Hauser & Fitch 2003 Hauser, Marc D.; Fitch, W. Tecumseh (2003). „What are the uniquely human components of the language faculty?”. Ур.: M.H. Christiansen and S. Kirby. Language Evolution: The States of the Art(PDF). Oxford University Press. Архивирано из оригинала(PDF) 8. 8. 2014. г.