1. Amazon. (2007). Amazon.com.
2. Retrieved June 27, 2007, from http://www.amazon.com
3. & (1989). Computability and logic (3rd ed.). Cambridge, England: Cambridge University Press.
4. (1791/1980). Life of Johnson (Ed., J.D. Fleeman, Rev., & P. Rogers, Intro.). Oxford, England: Oxford University Press. (Original work published 1791)
5. (1956). Society and knowledge. London: Allen & Unwin.