1. Hughes, J.: Why functional programming matters. Comput. J. 32(2), 98–107 (1989)
2. Bird, R., Wadler, P.: Introduction to Functional Programming. Prentice-Hall International, Upper Saddle River (1988)
3. Abelson, H., Sussman, G.J., Sussman, J.: Structure and Interpretation of Computer Programs, 2nd edn. MIT Press, Cambridge (1996)
4. Collins English Dictionary.
http://www.collinsdictionary.com
. Accessed 4 July 2014
5. Sommerville, I.: Software Engineering, 8th edn. Addison Wesley, Boston (2007)