"The World After September 11th". Noam Chomsky's speech at the American Friends Service Committee (AFSC) Conference at Tufts University, Massachusetts, December 8, 2001.
Andrea Moro, Noam Chomsky, Ivano Caponigro, Daniel B. Kane (2015). “The Boundaries of Babel: The Brain and the Enigma of Impossible Languages”, p.37, MIT Press