1. Aitchison Jean (2001). Language change: Progress or decay? (3rd ed.). New York, Cambridge University Press
2. Bag A.K. (1975). al-Biruni on Indian Arithmetic. Indian Journal for the History of Science 10: 174–184
3. Barber Charles (2000). The English language revised edition. New York, Cambridge University Press
4. Baron-Cohen Simon (1997). Mindblindness: An essay on autism and theory of mind. New York, Cambridge University Press
5. Boolos George (1979). The unprovability of consistency. New York, Cambridge University Press